[clang] [Clang] Add fake use emission to Clang with -fextend-lifetimes (PR #110102)

[Stephen Tozer via cfe-commits]

SLTozer wrote:

Pushed up a fix-forward commit, [8ad9e1e](https://github.com/llvm/llvm-project/commit/8ad9e1ecb7e565c2f99b4ef67517d1f37d1c80d0), that should fix the above issues; if issues still remain, I'll revert and recommit after fixing offline.

https://github.com/llvm/llvm-project/pull/110102