[llvm] [AMDGPU] Add synthetic regclass WWM_VGPR_32 for wwm reg operands (PR #86008)

[Christudasan Devadasan via llvm-commits]

cdevadas wrote:

Depends on https://github.com/llvm/llvm-project/pull/86006 https://github.com/llvm/llvm-project/pull/86007 (all pre-patches already in the commits list)

https://github.com/llvm/llvm-project/pull/86008