[InstCombine] Use CmpInst::Predicate with m_Cmp instead of ICmpInst::Predicate. NFC

There isn't really an ICmpInst version so we're just accessing the CmpInst version through inheritance.

llvm-svn: 307199
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index afc3b06..55486f1 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2458,7 +2458,7 @@
   }
 
   // not (cmp A, B) = !cmp A, B
-  ICmpInst::Predicate Pred;
+  CmpInst::Predicate Pred;
   if (match(&I, m_Not(m_OneUse(m_Cmp(Pred, m_Value(), m_Value()))))) {
     cast<CmpInst>(Op0)->setPredicate(CmpInst::getInversePredicate(Pred));
     return replaceInstUsesWith(I, Op0);