[llvm] [RISCV] Remove CalleeSavedInfo for Zcmp/save-restore-libcalls registers (PR #79535)

[Visoiu Mistrih Francis via llvm-commits]

francisvm wrote:

Last push should fix the test. Let me know if anyone has any more concerns, I'd like to put up other patches that need MIR testing.

https://github.com/llvm/llvm-project/pull/79535