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

[Tony Varghese via cfe-commits]

tonykuttai wrote:

> Aside from requiring constant initialization, I think that the pointer case should also require a string literal.

This will imply that deferred-pointer-to-named-global (`p = somestr`) need not be preserved in the final binary as we are doing now.

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