[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. 

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