[clang] [CIR] Add math and builtin intrinsics support (PR #175233)

[via cfe-commits]

adams381 wrote:

@andykaylor I've addressed your feedback about the noinline divergence from classic codegen in commit 2ce0ac32fd20.

**Changes made:**
- Removed the `hasEmittedBuiltinCall` tracking mechanism
- Now ALL non-always_inline functions get `noinline` at `-O0`, matching classic codegen exactly
- Added 154 OGCG checks to `builtin-floating-point.c` to verify CIR-produced LLVM matches classic codegen
- Updated test expectations in `builtin-fcmp-sse.c` and `avx512f16c-builtins.c`

The simplification removes ~17 lines of code and eliminates the special-case logic that was causing the divergence.

https://github.com/llvm/llvm-project/pull/175233