DAGCombiner: Fix crash in select(select) opt.

In case of different types used for the condition of the selects the
select(select) -> select(and) normalisation cannot be performed.

See also: http://reviews.llvm.org/D7622

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234763 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed