[llvm] [AMDGPU] Ensure that V_SET_INACTIVE inactive input is WWM computed (PR #98858)

[Jay Foad via llvm-commits]

jayfoad wrote:

I'm not convinced that this is a bug fix. Sure, if the wwm global flag is not set then we might not set the inactive lanes properly, but if nothing else in the shader is using wwm then why is that a problem?

https://github.com/llvm/llvm-project/pull/98858