chill added a comment.
FWIW, probably a single CALLSITE_DELAGATE macro could be used all over:
#define CALLSITE_DELEGATE(METHOD) \
InstrTy *II = getInstruction(); \
return isCall() \
? cast<CallInst>(II)->METHOD \
: cast<InvokeInst>(II)->METHOD
https://reviews.llvm.org/D34406