[llvm] [MIR] Serialize MachineFrameInfo::isCalleeSavedInfoValid() (PR #90561)

[David Tellenbach via llvm-commits]

dtellenbach wrote:

> Can we just print the empty list in this case?

That wouldn't help because the logic in MIRParser would still not find any callee-saved info and set it as not valid.

https://github.com/llvm/llvm-project/pull/90561