[llvm] [SPIRV] Addition of extension SPV_KHR_non_semantic_info and SPV_KHR_relaxed_extended_instruction (PR #169643)

[Manuel Carrasco via llvm-commits]

mgcarrasco wrote:

@aadeshps-mcw @michalpaszkowski I'm very sorry for commenting on this closed PR. I'm happy comment these points again when the PR is re-submitted. 

I did some more testing and found a failure related to include headers. The backend was emitting invalid SPIRV. The test case that documents this is here https://github.com/mgcarrasco/llvm-project/commit/9181f9dbd961d3c0fa5e504397c9ef78397b9ad3#diff-bbdcfb28067896ee61a24818e02ff93d63b9310142c13d0e520b09bc083bdb8d with a tentative fix. The fix is probably not fully correct, although it was enough to make the test pass.

https://github.com/llvm/llvm-project/pull/169643