[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.

llvm-svn: 304773
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index d5b93ca..55ced96 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -3310,9 +3310,7 @@
   // icmp eq|ne X, Y -> false|true if X != Y
   if (ICmpInst::isEquality(Pred) &&
       isKnownNonEqual(LHS, RHS, Q.DL, Q.AC, Q.CxtI, Q.DT)) {
-    LLVMContext &Ctx = LHS->getType()->getContext();
-    return Pred == ICmpInst::ICMP_NE ?
-      ConstantInt::getTrue(Ctx) : ConstantInt::getFalse(Ctx);
+    return Pred == ICmpInst::ICMP_NE ? getTrue(ITy) : getFalse(ITy);
   }
 
   if (Value *V = simplifyICmpWithBinOp(Pred, LHS, RHS, Q, MaxRecurse))