[clang] [CIR] Upstream overflow builtins (PR #166643)

[Henrich Lauko via cfe-commits]

================

----------------
xlauko wrote:

Update to follow test structure of other CIR tests:
- add LLVM check of expected LLVM
- add OGCG checks of expected llvm output of original codegen that should match through CIR produced LLVM

https://github.com/llvm/llvm-project/pull/166643