[llvm] [CodeGen][NPM] Port MachineBlockPlacementStats to NPM (PR #129853)

[Matt Arsenault via llvm-commits]

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@@ -30,6 +30,15 @@ class MachineBlockPlacementPass
                 function_ref<StringRef(StringRef)> MapClassName2PassName) const;
 };
 
+class MachineBlockPlacementStatsPass
+    : public PassInfoMixin<MachineBlockPlacementStatsPass> {
+
+public:
+  PreservedAnalyses run(MachineFunction &MF,
+                        MachineFunctionAnalysisManager &MFAM);
+  static bool isRequired() { return true; }
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arsenm wrote:

This pass just updates statistics? It certainly shouldn't be considered required. It pre-checks isFunctionInPrintList. Should the PM be directly managing this case? 

https://github.com/llvm/llvm-project/pull/129853