[llvm] [AMDGPU][InsertWaitCnts] Refactor some helper functions, NFC (PR #161160)

[Pierre van Houtryve via llvm-commits]

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@@ -748,6 +754,18 @@ class SIInstrInfo final : public AMDGPUGenInstrInfo {
     return isLDSDMA(MI) && MI.getOpcode() != AMDGPU::BUFFER_STORE_LDS_DWORD;
   }
 
+  static bool asynchronouslyWritesSCC(unsigned Opcode) {
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Pierre-vh wrote:

I can make the names more specific:

- isSBarrierSCCWrite
- isCBranchVCCZRead

We can then revert to more generic names if those predicates have to be expanded later, what do you think?

https://github.com/llvm/llvm-project/pull/161160