[clang] [LifetimeSafety] Handle xvalue operand of LValueToRValue cast (PR #192312)

[Utkarsh Saxena via cfe-commits]

https://github.com/usx95 approved this pull request.

LGTM. 

One request to run it on LLVM to verify no crashes.

https://github.com/llvm/llvm-project/pull/192312