[llvm] [llvm] Support multiple save/restore points in mir (PR #119357)

[Matt Arsenault via llvm-commits]

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@@ -74,6 +74,34 @@ class CalleeSavedInfo {
   bool isSpilledToReg()                    const { return SpilledToReg; }
 };
 
+class SaveRestorePoints {
+public:
+  using PointsMap = DenseMap<MachineBasicBlock *, std::vector<CalleeSavedInfo>>;
+
+private:
+  PointsMap Map;
+
+public:
+  const PointsMap &get() const { return Map; }
+
+  const std::vector<CalleeSavedInfo> getCSInfo(MachineBasicBlock *MBB) const {
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arsenm wrote:

Replace with at? there should be no default construction 

https://github.com/llvm/llvm-project/pull/119357