[InstSimplify] Avoid use of ConstantExpr::getICmp() (NFC)

Use ConstantFoldCompareInstOperands() instead.

Author: nikic

llvm/lib/Analysis/InstructionSimplify.cpp

@@ -3954,12 +3954,14 @@ static Value *simplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
           // LHS >s RHS.
           case ICmpInst::ICMP_SGT:
           case ICmpInst::ICMP_SGE:
-            return ConstantExpr::getICmp(ICmpInst::ICMP_SLT, C,
-                                         Constant::getNullValue(C->getType()));
+            return ConstantFoldCompareInstOperands(
+                ICmpInst::ICMP_SLT, C, Constant::getNullValue(C->getType()),
+                Q.DL);
           case ICmpInst::ICMP_SLT:
           case ICmpInst::ICMP_SLE:
-            return ConstantExpr::getICmp(ICmpInst::ICMP_SGE, C,
-                                         Constant::getNullValue(C->getType()));
+            return ConstantFoldCompareInstOperands(
+                ICmpInst::ICMP_SGE, C, Constant::getNullValue(C->getType()),
+                Q.DL);
 
           // If LHS is non-negative then LHS <u RHS.  If LHS is negative then
           // LHS >u RHS.