[InstSimplify] Use the getTrue/getFalse helpers and make sure we use the computed result type instead of hardcoding to i1. NFC

Currently, isKnownNonEqual punts on vectors so the hardcoding to i1 doesn't matter. But I plan to fix that in a future patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304773 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed