LLVM 17 regression: tests/ui/abi/stack-protector.rs no longer actually attempts stack-smashing

[durin42]

LLVM change 0d4a709 (https://reviews.llvm.org/D145210) appears to have broken the test for stack-protection. tests/ui/abi/stack-protector.rs fails both with and without stack protection enabled, because the test now makes it to the TEST BUG: stack smash unsuccessful panic, presumably because something new in LLVM's optimizations skips the stack smash.

Filing this bug and disabling the test in our Rust/LLVM HEADs CI for now so we see other (more urgent) breakage reliably.

[clubby789]

@rustbot label +A-llvm