Large const allocations no longer lead to graceful errors on aarch64

I just spun up an aarch64 (c6g.metal) instance to look at codegen, and I noticed that two of our UI tests do not pass:

    [ui] tests/ui/consts/large_const_alloc.rs
    [ui] tests/ui/consts/promoted_running_out_of_memory_issue-130687.rs

I can reduce one of the failing tests to this:

#![crate_type = "lib"]
pub const FOO: &[u8] = &[0_u8; (1 << 47) - 1];

If I am on an x86_64 host targeting aarch64-unknown-linux-gnu, using stable or nightly, this will immediately fail to compile with:

error[E0080]: evaluation of constant value failed
 --> demo.rs:2:25
  |
2 | pub const FOO: &[u8] = &[0_u8; (1 << 47) - 1];
  |                         ^^^^^^^^^^^^^^^^^^^^^ tried to allocate more memory than available to compiler

error: aborting due to 1 previous error

If my host is aarch64-unknown-linux-gnu using stable, I also get that diagnostic. But nightly toolchains on an aarch64 host allocate more and more memory, eventually dying with SIGKILL.

Bisection points to https://github.com/rust-lang/rust/pull/135262 as the cause, which suggests that this is a miscompile.

searched nightlies: from nightly-2024-01-01 to nightly-2025-01-23
regressed nightly: nightly-2025-01-13
searched commit range: https://github.com/rust-lang/rust/compare/eb54a50837ad4bcc9842924f27e7287ca66e294c...48a426eca9df23b24b3559e545cf88dee61d4de9
regressed commit: https://github.com/rust-lang/rust/commit/c0f6a1ce3f89a3240efe5c83839675e20f84e001

cargo bisect-rustc --script script.sh --start 2024-01-01 

This is worth further investigation. Of course it is plausible that a change to the CI configuration would alter the build artifacts from CI, but bisecting a test failure from a stage1 and stage2 toolchain to a CI change is odd.

Start with tests/ui/consts/large_const_alloc.rs and tests/ui/consts/promoted_running_out_of_memory_issue-130687.rs, reproducing the reduced constant on aarch64-unknown-linux-gnu. Read PR #135262 and compare the behavior around the regressed nightly range and commit c0f6a1ce; done means both UI tests fail gracefully rather than exhausting memory or being killed on an aarch64 host.