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

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman approved this pull request.

LGTM, I have no additional concerns but please wait for @hubert-reinterpretcast to accept before landing.

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