[llvm] [AMDGPU] Defaults for missing dimensions in SYCL required wg size (PR #72652)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

I still think we need to have one single spec for the metadata and not modify based on any is-this-language type annotations. The different producers and consumers should just agree on the operand constraints of the metadata 

https://github.com/llvm/llvm-project/pull/72652