visitor will now visit a CallInst and an InvokeInst with
instruction-specific visitors, then visit a generic CallSite visitor,
then delegate back to the Instruction visitor and the TerminatorInst
visitors depending on whether a call or an invoke originally. This will
be used in the soon-to-land inline cost rewrite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153811 91177308-0d34-0410-b5e6-96231b3b80d8
7384530c7c