Adjust 64-bit ARM data layouts for LLVM update

[maurer]

LLVM has updated data layouts to specify Fn32 on 64-bit ARM to avoid C++ accidentally underaligning functions when trying to comply with member function ABIs.

This should only affect Rust in cases where we had a similar bug (I don't believe we have one), but our data layout must match to generate code.

As a compatibility adaptatation, if LLVM is not version 19 yet, Fn32 gets voided from the data layout.

See llvm/llvm-project#90415

@rustbot label: +llvm-main
cc @krasimirgg
r? @durin42

[rustbot]

These commits modify compiler targets.
(See the Target Tier Policy.)

[durin42]

This looks basically fine to me, but I also only peripherally understand this so...

@rustbot r? compiler

[nikic]

@bors r+

[bors]

📌 Commit 4d397d3 has been approved by nikic

It is now in the queue for this repository.

[bors]

⌛ Testing commit 4d397d3 with merge db74fe1...

[rust-log-analyzer]

The job armhf-gnu failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

error: test run failed!
status: exit status: 101
command: RUST_TEST_THREADS="8" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/remote-test-client" "run" "0" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/resolve/no-std-3/a"
--- stdout -------------------------------
uploaded "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/resolve/no-std-3/a", waiting for result
--- stderr -------------------------------
thread 'main' panicked at src/tools/remote-test-client/src/main.rs:310:9:
client.read_exact(&mut header) failed with Connection reset by peer (os error 104)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[bors]

💔 Test failed - checks-actions

[nikic]

@bors retry remote-test-client failure

[bors]

⌛ Testing commit 4d397d3 with merge d71b3f4...

[bors]

☀️ Test successful - checks-actions
Approved by: nikic
Pushing d71b3f4 to master...

[rust-timer]

Finished benchmarking commit (d71b3f4): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.2%	[-1.2%, -1.2%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.3%	[-3.3%, -3.3%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.9%	[-4.1%, -3.7%]	2
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 673.849s -> 676.36s (0.37%)
Artifact size: 315.95 MiB -> 315.83 MiB (-0.04%)