Tracking issue for LLVM align attributes (-Z arg_align_attributes)

[scottmcm]

In theory we should be emitting LLVM align <n> attributes (https://llvm.org/docs/LangRef.html#attr-align) for references, since they're always aligned.

However, it turns out that these get inlined as assume calls, which (per the HACK comment in the code) block other optimizations, so they're currently disabled.

-Z flag was added in #49122

[nikic]

This flag has already been removed quite a while ago in #57021, so closing this.