Nightly `std` fails to build for WASM with `-C target-feature=+atomics`

Trying to build the standard library for the wasm32-unknown-unknown target with -C target-feature=+atomics fails using the latest nightly compiler. Specifically, this happens:

error[E0583]: file not found for module `futex`
  --> /.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/std/src/sys/wasm/mod.rs:55:13
   |
55 |             mod futex;
   |             ^^^^^^^^^^
   |
   = help: to create the module `futex`, create file "/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/std/src/sys/wasm/../unix/locks/futex.rs" or "/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/std/src/sys/wasm/../unix/locks/futex/mod.rs"

error[E0432]: unresolved imports `futex::Mutex`, `futex::MovableMutex`, `futex::Condvar`, `futex::MovableCondvar`
  --> /.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/std/src/sys/wasm/mod.rs:57:36
   |
57 |             pub(crate) use futex::{Mutex, MovableMutex, Condvar, MovableCondvar};
   |                                    ^^^^^  ^^^^^^^^^^^^  ^^^^^^^  ^^^^^^^^^^^^^^ no `MovableCondvar` in `sys::wasm::locks::futex`
   |                                    |      |             |
   |                                    |      |             no `Condvar` in `sys::wasm::locks::futex`
   |                                    |      no `MovableMutex` in `sys::wasm::locks::futex`
   |                                    no `Mutex` in `sys::wasm::locks::futex`

Meta

rustc --version --verbose:

rustc 1.64.0-nightly (fe3342816 2022-08-01)
binary: rustc
commit-hash: fe3342816a282949f014caa05ea2e669ff9d3d3c
commit-date: 2022-08-01
host: x86_64-apple-darwin
release: 1.64.0-nightly
LLVM version: 14.0.6

Fixed by #99800