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

[Justin Bogner via cfe-commits]

bogner wrote:

> I think the forward fix has been identified, and importantly it will take a bit longer to revert than to submit the fix (adding triples to the tests), because there are 4 commits that need to be reverted and I need to run a quick build to ensure that nothing is broken by the revert itself - I'm running that build right now, but will push the fix commit up while that build is running since that might fix the problem sooner.

Commented on the commit but I'm not sure if that sends notifications. FWIW I think you can use `%itanium_abi_triple` for this kind of thing rather than an entirely explicit triple

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