[llvm] [AMDGPU] Defaults for missing dimensions in SYCL required wg size (PR #68872)

[Jakub Chlanda via llvm-commits]

jchlanda wrote:

Closing this PR, we've decide to handle it internally in SYCL (https://github.com/intel/llvm/pull/13600). It aligns with OpenCL's and always pads missing dimensions with `1`.

https://github.com/llvm/llvm-project/pull/68872