[llvm] [AMDGPU] IGLP: Fix static variables (PR #137549)

[Matt Arsenault via llvm-commits]

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@@ -614,7 +679,11 @@ class SIMachineFunctionInfo final : public AMDGPUMachineFunctionInfo,
   // load/store is enabled.
   IndexedMap<uint32_t, VGPRBlock2IndexFunctor> MaskForVGPRBlockOps;
 
-private:
+  DenseMap<const MachineInstr *, MFMASmallGemmSingleWaveCache>
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arsenm wrote:

This needs documentation. It's also kind of terrible that there's an instruction pointer here 

https://github.com/llvm/llvm-project/pull/137549