[clang] [llvm] [clang][SPIR-V] Implement -fspv-preserve-interface (PR #196404)

[Juan Manuel Martinez Caamaño via cfe-commits]

jmmartinez wrote:

> @bogner thanks for the review. Would you be able to submit the PR for me? I don't have write access to the repo. Thanks.

I'll do it.

https://github.com/llvm/llvm-project/pull/196404