[llvm] [AMDGPU] Fix GFX1250 hazard: S_SET_VGPR_MSB dropped (PR #184904)

[Jay Foad via llvm-commits]

jayfoad wrote:

> To me it is way easier to just mitigate the problem right in the VGPR lowering. The mitigation function does not use anything essential from the hazard recognizer.

OK, agreed. Thanks for the vcmpx/permlane example.

https://github.com/llvm/llvm-project/pull/184904