Fix and/or/xor (cast A), (cast B) --> cast (and/or/xor A, B)

Fix and/or/xor (cast A), (cast B) --> cast (and/or/xor A, B)
The cast patch introduced the possibility that the wrong cast opcode
could be used and that this transform could trigger on different kinds
of cast operations. This patch rectifies that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32538 91177308-0d34-0410-b5e6-96231b3b80d8