[IR] Make intrinsic checks more efficient (NFC) (#148682)

Directly cast the callee operand instead of going through
getCalledFunction(). We can do this because for intrinsics the function
type between the call and the function is guaranteed to match.

This is a minor compile-time improvement as is, but has a much bigger
impact with a future change that makes getCalledFunction() more
expensive.

There is some code duplication between these four uses, but they are
each just different enough that representing one in terms of another
would be less efficient.

0 files changed, 0 insertions, 0 deletions