[InstCombine] name change: foldShuffledBinop -> foldVectorBinop; NFC

This function will deal with more than shuffles with D50992, and I 
have another potential per-element fold that could live here.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343692 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed