[llvm] [AVR] Support stack realignment (PR #187129)

[Matt Arsenault via llvm-commits]

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@@ -2586,6 +2619,37 @@ bool AVRExpandPseudo::expand<AVR::SPWRITE>(Block &MBB, BlockIt MBBI) {
   return true;
 }
 
+template <> bool AVRExpandPseudo::expand<AVR::FRMSP>(Block &MBB, BlockIt MBBI) {
+  MachineInstr &MI = *MBBI;
+  MachineFunction &MF = *MI.getMF();
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arsenm wrote:

Should not get the function from the MachineInstr, especially when you have blocks 

https://github.com/llvm/llvm-project/pull/187129