[AMDGPU] GCNHazardRecognizer: ignore all meta instructions

[foad]

Summary

This is hopefully NFC, but should be more robust in ignoring all
instructions that should be ignored, instead of just some of them.

llvm/lib/Target/AMDGPU/GCNHazardRecognizer.cpp

void GCNHazardRecognizer::AdvanceCycle() {
   if (!CurrCycleInstr) {
     EmittedInstrs.push_front(nullptr);
     return;
   }
 
   // Do not track non-instructions which do not affect the wait states.
   // If included, these instructions can lead to buffer overflow such that
   // detectable hazards are missed.
-  if (CurrCycleInstr->isImplicitDef() || CurrCycleInstr->isDebugInstr() ||
-      CurrCycleInstr->isKill()) {
+  if (CurrCycleInstr->isMetaInstruction()) {
     CurrCycleInstr = nullptr;
     return;
   }
 
   if (CurrCycleInstr->isBundle()) {
     processBundle();
     return;
   }