[InstCombine] add test for possible zext-phi transform; NFC

The datalayout doesn't include i1, so we don't do a potential shrink and sink transform.

Example based on discussion here:
http://lists.llvm.org/pipermail/llvm-dev/2017-January/109631.html


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293656 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed