[llvm] [Xtensa] Implement lowering SELECT_CC, SETCC. (PR #97017)

[Andrei Safronov via llvm-commits]

andreisfr wrote:

@arsenm , @jyknight,  @MaskRay , @s-barannikov , PTAL to this PR whenever you have the time.

https://github.com/llvm/llvm-project/pull/97017