[clang] [llvm] Reland "[HLSL] Implement the reflect HLSL function" (PR #125599)

[Deric Cheung via cfe-commits]

Icohedron wrote:

Because the "underlying" -- though still not fully understood -- cause of the test failure under hwasan was found (refer to my [comment](https://github.com/llvm/llvm-project/issues/124045#issuecomment-2669906382) from issue #124045), I have re-added support for running the test under hwasan and fixed the issue with the RUN lines that made the test fail under hwasan in the first place.

I think this is the way forward, unless we think the error test should be omitted and relegated to a separate PR.

https://github.com/llvm/llvm-project/pull/125599