[llvm] [AMDGPU] Generate waterfall for calls with SGPR(inreg) argument (PR #146997)

[via llvm-commits]

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@@ -84,6 +90,9 @@ struct SIInstrWorklist {
 
   SetVector<MachineInstr *> &getDeferredList() { return DeferredList; }
 
+  DenseMap<MachineInstr *, V2PhysSCopyInfo> WaterFalls;
+  DenseMap<MachineInstr *, bool> V2SPhyCopiesToErase;
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Shoreshen wrote:

Hi @arsenm , these 2 seems only work inside [SIInstrInfo.cpp](https://github.com/llvm/llvm-project/pull/146997/files/d88c03dea7670f74d934e70d8621bc1c02e368c7#diff-744f96b5d6f7f2ed21a65e4b3717f9bf26b5fbaad0aeb6c043d49d8b3458409e), so I put it inside the `moveToVALU` function.

If need to move to [SIInstrInfo.cpp](https://github.com/llvm/llvm-project/pull/146997/files/d88c03dea7670f74d934e70d8621bc1c02e368c7#diff-744f96b5d6f7f2ed21a65e4b3717f9bf26b5fbaad0aeb6c043d49d8b3458409e), since it goes across between different files, I may have to pass it in using function parameter??

https://github.com/llvm/llvm-project/pull/146997