ICE: ` no entry found for key`, `expr.rs`

[matthiaskrgr]

auto-reduced (treereduce-rust):

#![feature(generic_const_exprs)]
#![feature(non_lifetime_binders)]

fn a()
where
    for<T, const N: usize, const NP: usize = { N + 1usize }> T: Copy,
{
}

original:

fn a() where for<T, const N: usize, const NP: usize = {N+1usize}> T: Copy { }

Version information

rustc 1.77.0-nightly (e51e98dde 2023-12-31)
binary: rustc
commit-hash: e51e98dde6a60637b6a71b8105245b629ac3fe77
commit-date: 2023-12-31
host: x86_64-unknown-linux-gnu
release: 1.77.0-nightly
LLVM version: 17.0.6

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc --crate-type=lib -Zcrate-attr=feature(generic_const_exprs) -Zcrate-attr=feature(non_lifetime_binders)

Program output

warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
 --> <crate attribute>:1:9
  |
1 | feature(generic_const_exprs)
  |         ^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
  = note: `#[warn(incomplete_features)]` on by default

warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes
 --> <crate attribute>:1:9
  |
1 | feature(non_lifetime_binders)
  |         ^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information

thread 'rustc' panicked at compiler/rustc_mir_build/src/thir/cx/expr.rs:888:59:
no entry found for key
stack backtrace:
   0:     0x7f361878b946 - std::backtrace_rs::backtrace::libunwind::trace::h44f4ca7c442c0986
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7f361878b946 - std::backtrace_rs::backtrace::trace_unsynchronized::h8e72beef8f98799e
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f361878b946 - std::sys_common::backtrace::_print_fmt::had1f7322c7191a83
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7f361878b946 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hc02075f68ac68e83
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f36187de060 - core::fmt::rt::Argument::fmt::h4fb797bf569c9381
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/fmt/rt.rs:142:9
   5:     0x7f36187de060 - core::fmt::write::h6f1ea15fe9368d17
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/fmt/mod.rs:1120:17
   6:     0x7f361877f36f - std::io::Write::write_fmt::haaa4143b58137630
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/io/mod.rs:1810:15
   7:     0x7f361878b724 - std::sys_common::backtrace::_print::h16f1f390d8dff6aa
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f361878b724 - std::sys_common::backtrace::print::h7a4cfc718891723c
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f361878e4b7 - std::panicking::default_hook::{{closure}}::h66f09592313f4ce8
  10:     0x7f361878e219 - std::panicking::default_hook::he45e0a376ce42f7d
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/panicking.rs:292:9
  11:     0x7f361b56605c - std[59bbd359e4a0812d]::panicking::update_hook::<alloc[9e8bbef5278c9f16]::boxed::Box<rustc_driver_impl[f5f02e8ab7f89dcf]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f361878ec06 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h0ebdda5c503ff158
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/alloc/src/boxed.rs:2029:9
  13:     0x7f361878ec06 - std::panicking::rust_panic_with_hook::h4f38919015b1c60f
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/panicking.rs:783:13
  14:     0x7f361878e952 - std::panicking::begin_panic_handler::{{closure}}::h6e933e94ded3024f
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/panicking.rs:657:13
  15:     0x7f361878be46 - std::sys_common::backtrace::__rust_end_short_backtrace::h4efef00f0bd07d56
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/sys_common/backtrace.rs:171:18
  16:     0x7f361878e6b0 - rust_begin_unwind
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/panicking.rs:645:5
  17:     0x7f36187da765 - core::panicking::panic_fmt::h3f2350d70561f7cb
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/panicking.rs:72:14
  18:     0x7f36187da513 - core::panicking::panic_display::hd10cbfc2d262f172
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/panicking.rs:196:5
  19:     0x7f36187da513 - core::panicking::panic_str::hbed90c8c1c7b42fd
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/panicking.rs:171:5
  20:     0x7f36187da513 - core::option::expect_failed::h814960b2c8b9ead7
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/core/src/option.rs:1980:5
  21:     0x7f361cd360eb - <rustc_mir_build[92ecac31500debc4]::thir::cx::Cx>::mirror_expr
  22:     0x7f361cd313a3 - <rustc_mir_build[92ecac31500debc4]::thir::cx::Cx>::mirror_expr
  23:     0x7f361cd2ddd7 - <rustc_mir_build[92ecac31500debc4]::thir::cx::Cx>::mirror_block
  24:     0x7f361cd2f53d - <rustc_mir_build[92ecac31500debc4]::thir::cx::Cx>::mirror_expr
  25:     0x7f361cd2943d - rustc_mir_build[92ecac31500debc4]::thir::cx::thir_body
  26:     0x7f361cd28d72 - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::thir_body::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 16usize]>>
  27:     0x7f361ce29440 - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::VecCache<rustc_span[44814e3eac9e4a35]::def_id::LocalDefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  28:     0x7f361ce28fa5 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::thir_body::get_query_non_incr::__rust_end_short_backtrace
  29:     0x7f361ce2c4a2 - rustc_middle[7d80ff9c88f366f3]::query::plumbing::query_get_at::<rustc_query_system[cdab7429fb42dda2]::query::caches::VecCache<rustc_span[44814e3eac9e4a35]::def_id::LocalDefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 16usize]>>>
  30:     0x7f361c814413 - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::thir_abstract_const::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 16usize]>>
  31:     0x7f361c81431b - <rustc_query_impl[6eb9e4a88fa21aca]::query_impl::thir_abstract_const::dynamic_query::{closure#2} as core[f50a4b4ddb6878bb]::ops::function::FnOnce<(rustc_middle[7d80ff9c88f366f3]::ty::context::TyCtxt, rustc_span[44814e3eac9e4a35]::def_id::DefId)>>::call_once
  32:     0x7f361c8d39a0 - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::DefaultCache<rustc_span[44814e3eac9e4a35]::def_id::DefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  33:     0x7f361c8d31e1 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::thir_abstract_const::get_query_non_incr::__rust_end_short_backtrace
  34:     0x7f361cb0b6ff - rustc_mir_build[92ecac31500debc4]::build::mir_built
  35:     0x7f361cb0b5ed - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_built::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>
  36:     0x7f361c965c43 - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::VecCache<rustc_span[44814e3eac9e4a35]::def_id::LocalDefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  37:     0x7f361c9655d0 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace
  38:     0x7f3619da928e - rustc_mir_transform[8186e48857664e14]::check_unsafety::unsafety_check_result
  39:     0x7f361c9659c7 - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::unsafety_check_result::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>
  40:     0x7f361c965c43 - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::VecCache<rustc_span[44814e3eac9e4a35]::def_id::LocalDefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  41:     0x7f361c965750 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::unsafety_check_result::get_query_non_incr::__rust_end_short_backtrace
  42:     0x7f361c966c39 - rustc_mir_transform[8186e48857664e14]::mir_const
  43:     0x7f361c966b67 - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_const::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>
  44:     0x7f361c965c43 - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::VecCache<rustc_span[44814e3eac9e4a35]::def_id::LocalDefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  45:     0x7f361c965690 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_const::get_query_non_incr::__rust_end_short_backtrace
  46:     0x7f361c96544c - rustc_middle[7d80ff9c88f366f3]::query::plumbing::query_get_at::<rustc_query_system[cdab7429fb42dda2]::query::caches::VecCache<rustc_span[44814e3eac9e4a35]::def_id::LocalDefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>>
  47:     0x7f361cfba6da - rustc_mir_transform[8186e48857664e14]::mir_const_qualif
  48:     0x7f361cfba68b - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_const_qualif::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 5usize]>>
  49:     0x7f361cfb9a30 - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::DefaultCache<rustc_span[44814e3eac9e4a35]::def_id::DefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 5usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  50:     0x7f361cfb9796 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_const_qualif::get_query_non_incr::__rust_end_short_backtrace
  51:     0x7f361aae3179 - rustc_mir_transform[8186e48857664e14]::mir_promoted
  52:     0x7f361ce2915e - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_promoted::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 16usize]>>
  53:     0x7f361ce2942a - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::VecCache<rustc_span[44814e3eac9e4a35]::def_id::LocalDefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  54:     0x7f361ce29063 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_promoted::get_query_non_incr::__rust_end_short_backtrace
  55:     0x7f361d6d3a30 - rustc_borrowck[873e5fa24eb195b7]::mir_borrowck
  56:     0x7f361d6d3979 - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>
  57:     0x7f361c965c43 - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::VecCache<rustc_span[44814e3eac9e4a35]::def_id::LocalDefId, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  58:     0x7f361c965810 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
  59:     0x7f361d15a478 - rustc_interface[8dea96efab884454]::passes::analysis
  60:     0x7f361d159f5f - rustc_query_impl[6eb9e4a88fa21aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6eb9e4a88fa21aca]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 1usize]>>
  61:     0x7f361d797a64 - rustc_query_system[cdab7429fb42dda2]::query::plumbing::try_execute_query::<rustc_query_impl[6eb9e4a88fa21aca]::DynamicConfig<rustc_query_system[cdab7429fb42dda2]::query::caches::SingleCache<rustc_middle[7d80ff9c88f366f3]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[6eb9e4a88fa21aca]::plumbing::QueryCtxt, false>
  62:     0x7f361d797855 - rustc_query_impl[6eb9e4a88fa21aca]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  63:     0x7f361d82d094 - rustc_interface[8dea96efab884454]::interface::run_compiler::<core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>, rustc_driver_impl[f5f02e8ab7f89dcf]::run_compiler::{closure#0}>::{closure#0}
  64:     0x7f361d7b7306 - std[59bbd359e4a0812d]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[8dea96efab884454]::util::run_in_thread_with_globals<rustc_interface[8dea96efab884454]::util::run_in_thread_pool_with_globals<rustc_interface[8dea96efab884454]::interface::run_compiler<core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>, rustc_driver_impl[f5f02e8ab7f89dcf]::run_compiler::{closure#0}>::{closure#0}, core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>>::{closure#0}, core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>>
  65:     0x7f361d7b7133 - <<std[59bbd359e4a0812d]::thread::Builder>::spawn_unchecked_<rustc_interface[8dea96efab884454]::util::run_in_thread_with_globals<rustc_interface[8dea96efab884454]::util::run_in_thread_pool_with_globals<rustc_interface[8dea96efab884454]::interface::run_compiler<core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>, rustc_driver_impl[f5f02e8ab7f89dcf]::run_compiler::{closure#0}>::{closure#0}, core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>>::{closure#0}, core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[f50a4b4ddb6878bb]::result::Result<(), rustc_span[44814e3eac9e4a35]::ErrorGuaranteed>>::{closure#1} as core[f50a4b4ddb6878bb]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  66:     0x7f3618798b35 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hfced58be344e2c05
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/alloc/src/boxed.rs:2015:9
  67:     0x7f3618798b35 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h7842a7154462ae57
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/alloc/src/boxed.rs:2015:9
  68:     0x7f3618798b35 - std::sys::unix::thread::Thread::new::thread_start::ha365c5d9b9d0ac99
                               at /rustc/e51e98dde6a60637b6a71b8105245b629ac3fe77/library/std/src/sys/unix/thread.rs:108:17
  69:     0x7f36185849eb - <unknown>
  70:     0x7f36186087cc - <unknown>
  71:                0x0 - <unknown>

error: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.77.0-nightly (e51e98dde 2023-12-31) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib -Z crate-attr=feature(generic_const_exprs) -Z crate-attr=feature(non_lifetime_binders) -Z dump-mir-dir=dir

query stack during panic:
#0 [thir_body] building THIR for `a::{constant#0}`
#1 [thir_abstract_const] building an abstract representation for `a::{constant#0}`
#2 [mir_built] building MIR for `a::{constant#0}`
#3 [unsafety_check_result] unsafety-checking `a::{constant#0}`
#4 [mir_const] preparing `a::{constant#0}` for borrow checking
#5 [mir_const_qualif] const checking `a::{constant#0}`
#6 [mir_promoted] promoting constants in MIR for `a::{constant#0}`
#7 [mir_borrowck] borrow-checking `a::{constant#0}`
#8 [analysis] running analysis passes on this crate
end of query stack
warning: 2 warnings emitted

[matthiaskrgr]

Regression in nightly-2023-02-18

commit[0] 2023-02-16: Auto merge of #108127 - matthiaskrgr:rollup-kpzfc6j, r=matthiaskrgr
commit[1] 2023-02-16: Auto merge of #107833 - Zoxc:arena-query-clean, r=cjgillot
commit[2] 2023-02-17: Auto merge of #108145 - matthiaskrgr:rollup-bgadak1, r=matthiaskrgr
commit[3] 2023-02-17: Auto merge of #107753 - kylematsuda:type-of, r=BoxyUwU
commit[4] 2023-02-17: Auto merge of #108058 - Zoxc:query-ctxtx-byval, r=cjgillot
commit[5] 2023-02-17: Auto merge of #107965 - BoxyUwU:add_const_arg_has_type_predicate, r=compiler-errors
commit[6] 2023-02-17: Auto merge of #108159 - matthiaskrgr:rollup-5k2j7cx, r=matthiaskrgr
commit[7] 2023-02-17: Auto merge of #108075 - WaffleLapkin:de-arena-allocates-you-OwO, r=Nilstrieb

[fmease]

Ah, the recent PR #119042 could've fixed this if it had denied defaults on higher-ranked const parameters, too.
Imma make up for that.

Edit: Oh, that wouldn't fully address this issue...

[fmease]

We're not even rejecting fn f() where for<T = (), const K: () = {}> (): {}, that's bad.