[llvm] Revert "AMDGPU: Don't avoid clamp of bit shift in BFE pattern (#115372)" (PR #116091)

[Changpeng Fang via llvm-commits]

changpeng wrote:

> > > Please say why in the description.
> > 
> > 
> > We are going to revert the original patch for bfe patterns. We believe the optimization is just the corner cases and does not deserve the cost of compilation time.
> 
> This comment is not part of the commit description

I know.  Already updated the commit description (in different words though)

https://github.com/llvm/llvm-project/pull/116091