[llvm] [AMDGPU] Fix missing waitcnt after buffer_wbl2 (PR #178316)

[Austin Kerbow via llvm-commits]

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@@ -2701,7 +2711,11 @@ void SIInsertWaitcnts::updateEventWaitcntAfter(MachineInstr &Inst,
     if (!SIInstrInfo::isLDSDMA(Inst) && FlatASCount > 1)
       ScoreBrackets->setPendingFlat();
   } else if (SIInstrInfo::isVMEM(Inst) &&
-             !llvm::AMDGPU::getMUBUFIsBufferInv(Inst.getOpcode())) {
+             ((!llvm::AMDGPU::getMUBUFIsBufferInv(Inst.getOpcode()) ||
+               Inst.getOpcode() == AMDGPU::BUFFER_WBL2))) {
+    // BUFFER_WBL2 is included here because unlike  invalidates, has to be
----------------
kerbowa wrote:

```suggestion
    // BUFFER_WBL2 is included here because unlike invalidates, has to be
```

https://github.com/llvm/llvm-project/pull/178316