Large const alloc does not fail gracefully on AIX

[mustartt]

The following test cases either hangs or tries to honor the allocation and get sigkilled on AIX.

tests/ui/consts/large_const_alloc.rs

const FOO: () = {
    // 128 TiB, unlikely anyone has that much RAM
    let x = [0_u8; (1 << 47) - 1];
    //~^ ERROR evaluation of constant value failed
};

tests/ui/consts/promoted_running_out_of_memory_issue-130687.rs

[workingjubilee]

I do not believe the code in question is testing "if we fail, fail gracefully", but rather that we handle the failure case of failing to allocate at all. Hitting SIGKILL is an acceptable consequence.

[mustartt]

I guess getting SIGKILL is an acceptable result vs passing. Regardless these these large const alloc tests does not interact well on AIX, as it continuously requests page space until it runs out.

I will close this and mark #137967 and interacting badly. Thanks for the insight :)