Address comments.

Author: kazutakahirata

llvm/utils/TableGen/Common/CodeGenDAGPatterns.cpp

@@ -3508,7 +3508,7 @@ void CodeGenDAGPatterns::FindPatternInputsAndOutputs(
         Val->getDef()->isSubClassOf("PointerLikeRegClass")) {
       if (Dest->getName().empty())
         I.error("set destination must have a name!");
-      if (!InstResults.try_emplace(Dest->getName(), Dest).second)
+      if (!InstResults.insert_or_assign(Dest->getName(), Dest).second)
         I.error("cannot set '" + Dest->getName() + "' multiple times");
     } else if (Val->getDef()->isSubClassOf("Register")) {
       InstImpResults.push_back(Val->getDef());