[InstComb] Use IsaPred in place of match_fn

Author: artagnon

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

@@ -1340,7 +1340,7 @@ Instruction *InstCombinerImpl::foldICmpWithConstant(ICmpInst &Cmp) {
     return nullptr;
 
   if (auto *Phi = dyn_cast<PHINode>(Op0))
-    if (all_of(Phi->operands(), match_fn(m_Constant()))) {
+    if (all_of(Phi->operands(), IsaPred<Constant>)) {
       SmallVector<Constant *> Ops;
       for (Value *V : Phi->incoming_values()) {
         Constant *Res =