Use emplace_back instead of push_back (NFC)

Author: GkvJwa

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -2953,8 +2953,7 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(
       if (MSInfo->getPointOfInstantiation().isInvalid()) {
         SourceLocation Loc = D->getLocation(); // FIXME
         MSInfo->setPointOfInstantiation(Loc);
-        SemaRef.PendingLocalImplicitInstantiations.push_back(
-            std::make_pair(Function, Loc));
+        SemaRef.PendingLocalImplicitInstantiations.emplace_back(Function, Loc);
       }
     }
   }
@@ -5479,8 +5478,7 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
       // definition will be required).
       assert(!Recursive);
       Function->setInstantiationIsPending(true);
-      PendingInstantiations.push_back(
-        std::make_pair(Function, PointOfInstantiation));
+      PendingInstantiations.emplace_back(Function, PointOfInstantiation);
 
       if (llvm::isTimeTraceVerbose()) {
         llvm::timeTraceAddInstantEvent("DeferInstantiation", [&] {
@@ -6204,8 +6202,7 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
   // unit.
   if (!Def && !DefinitionRequired) {
     if (TSK == TSK_ExplicitInstantiationDefinition) {
-      PendingInstantiations.push_back(
-        std::make_pair(Var, PointOfInstantiation));
+      PendingInstantiations.emplace_back(Var, PointOfInstantiation);
     } else if (TSK == TSK_ImplicitInstantiation) {
       // Warn about missing definition at the end of translation unit.
       if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&