[clang] [CIR] Upstream CUDA mangling test with LLVM and OGCG verification (PR #184444)

[Srivarshitha M via cfe-commits]

16srivarshitha wrote:

Thanks for the feedback! I've moved the test and the mock cuda.h header to clang/test/CodeGenCUDA/ to follow the standard Clang directory structure. I've also updated the include paths accordingly. 

https://github.com/llvm/llvm-project/pull/184444