[Lanai] Make DelaySlotFiller handle implicit call operands
This allowed incorrectly moving an instruction defining a register
implicitly used by the call into the delay slot when the call dependend
on that register. We fix this by only skipping regmask operands.
Co-Authored-By: Jacques Pienaar <jpienaar@google.com>
Reviewers: jpienaar
Pull Request: https://github.com/llvm/llvm-project/pull/206192
