[clang] [llvm] [AMDGPU][WIP] Extend permlane16, permlanex16 and permlane64 intrinsic lowering for generic types (PR #92725)

[Vikram Hegde via cfe-commits]

vikramRH wrote:

1. Added/updated tests for permlanex16, permlane64
2. This needs https://github.com/llvm/llvm-project/pull/89217 to land first so that only incremental changes can be reviewed. 

https://github.com/llvm/llvm-project/pull/92725