[clang] [CIR][OpenCL] Add kernel argument metadata attribute (PR #199530)

[Konstantinos Parasyris via cfe-commits]

https://github.com/koparasy commented:

Overall it looks good, could we introduce the `CIR_LangAddressSpace` (https://github.com/llvm/llvm-project/blob/main/clang/include/clang/CIR/Dialect/IR/CIREnumAttr.td#L39)? 

https://github.com/llvm/llvm-project/pull/199530