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

[Matt Arsenault via llvm-commits]

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@@ -651,6 +679,57 @@ static void insertCSRRestores(MachineBasicBlock &RestoreBlock,
   }
 }
 
+static void fillCSInfoPerBB(MachineFrameInfo &MFI,
+                            DenseMap<Register, CalleeSavedInfo *> &RegToInfo,
+                            MBBVector &PrologEpilogBlocks, bool isSave) {
+  std::vector<CalleeSavedInfo> CSIV = {};
+  std::vector<CalleeSavedInfo> GCSIV = {};
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arsenm wrote:

```suggestion
  std::vector<CalleeSavedInfo> CSIV;
  std::vector<CalleeSavedInfo> GCSIV;
```

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