[InstCombine] simplify binops before trying other folds

This is outwardly NFC from what I can tell, but it should be more efficient 
to simplify first (despite the name, SimplifyAssociativeOrCommutative does
not actually simplify as InstSimplify does - it creates/morphs instructions).

This should make it easier to refactor duplicated code that runs for all binops.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335258 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed