[llvm] [SPIR-V] Align memory scopes with SPIR-V specification and LLVM expectations and change default mem scope value (PR #108528)

[Vyacheslav Levytskyy via llvm-commits]

VyacheslavLevytskyy wrote:

@AlexVlx @arsenm @michalpaszkowski @MrSidims What do you think about this small and clear change as a way to resolve terminology and default portions of our discussion from https://github.com/llvm/llvm-project/pull/106429 ?

I don't update any test yet until I know your opinion.

https://github.com/llvm/llvm-project/pull/108528