InstCombine: Ensure select condition types are identical before merging

Selection conditions may be vectors or scalars.  Make sure InstCombine
doesn't indiscriminately assume that a select which is value dependent
on another select have identical select condition types.

This fixes PR22773.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231156 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed