[clang] [CIR] Add cir-simplify pass (PR #138317)

[via cfe-commits]

Andres-Salamanca wrote:

> @bcardosolopes Adding a test for C++ -> CIR depends on #138003 which adds lowering for `?:`, `&&` and `||`. Since this one's ready to be merged apart from your remark IMO I'd add that test in #138003

I think you're referring to this PR: https://github.com/llvm/llvm-project/pull/138156

https://github.com/llvm/llvm-project/pull/138317