Revert "cmGlobalGenerator: Fix value type pushed into autogens vector"

This reverts commit ae6fc555a7.

Use the more-natural make_pair algorithm.  The compiler motivating
the need for this is not supported as a host anymore.

Source/cmGlobalGenerator.cxx

@@ -1387,7 +1387,7 @@ void cmGlobalGenerator::CreateQtAutoGeneratorsTargets(AutogensType &autogens)
           cmQtAutoGenerators autogen;
           if(autogen.InitializeAutogenTarget(&target))
             {
-            autogens.push_back(AutogensType::value_type(autogen, &target));
+            autogens.push_back(std::make_pair(autogen, &target));
             }
           }
         }