[llvm] [AMDGPU] Unused sdst writing to null (PR #133229)

[Matt Arsenault via llvm-commits]

================
@@ -973,6 +973,11 @@ bool SIShrinkInstructions::run(MachineFunction &MF) {
         continue;
       }
 
+      if (TII->isVOP3(MI.getOpcode()) &&
+          TII->hasVALU32BitEncoding(MI.getOpcode())) {
----------------
arsenm wrote:

Merge this with the existing hasVALU32BitEncoding check below 

https://github.com/llvm/llvm-project/pull/133229