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

[Michael Maitland via llvm-commits]

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@@ -37,6 +52,8 @@ class CalleeSavedInfo {
     int FrameIdx;
     unsigned DstReg;
   };
+  std::vector<MachineBasicBlock *> SpilledIn;
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michaelmaitland wrote:

Should we reuse CSInfoPerSave and CSInfoPerRestore instead of duplicating this information to reduce memory footprint? I think those data structures contain MBB that is spilled in and restored in respectively.

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