[llvm] [AMDGPU] Optimize out s_barrier_signal/_wait (PR #116993)

[Shilei Tian via llvm-commits]

================
@@ -0,0 +1,55 @@
+; RUN: llc -global-isel=0 -mtriple=amdgcn -mcpu=gfx1200 < %s | FileCheck %s
----------------
shiltian wrote:

I strongly suggest to auto gen the check lines please, which can make other's life much easier in the future.

https://github.com/llvm/llvm-project/pull/116993