[clang] [llvm] [Clang][AIX] Add -mloadtime-comment-vars flag to preserve identifying variables (PR #187986)

[Hubert Tong via cfe-commits]

hubert-reinterpretcast wrote:

> Is this effectively a different form of `__attribute__((used))`?

That depends on how one chooses to draw the line.

Is this similar to `__attribute__((__used__))`?
Yes, very much so.

Is this the same semantically as `__attribute__((__used__))`?
No, because it affects linker GC.

Is this the same semantically as `__attribute__((__retain__))`?
No, because the mechanism by which linker GC is affected is not (and is not intended to be) equivalent.

https://github.com/llvm/llvm-project/pull/187986