microoptimizations: call getitemInternal and callFunc<S, NOT_REWRITABLE>

src/runtime/dict.cpp

@@ -633,7 +633,7 @@ void dictMerge(BoxedDict* self, Box* other) {
     assert(keys);
 
     for (Box* k : keys->pyElements()) {
-        self->d[k] = getitem(other, k);
+        self->d[k] = getitemInternal<CXX>(other, k);
     }
 }
 

src/runtime/objmodel.cpp

@@ -3267,7 +3267,7 @@ static Box* _callFuncHelper(BoxedFunctionBase* func, ArgPassSpec argspec, Box* a
                             void** extra_args) {
     Box** args = (Box**)extra_args[0];
     auto keyword_names = (const std::vector<BoxedString*>*)extra_args[1];
-    return callFunc<S>(func, NULL, argspec, arg1, arg2, arg3, args, keyword_names);
+    return callFunc<S, NOT_REWRITABLE>(func, NULL, argspec, arg1, arg2, arg3, args, keyword_names);
 }
 
 typedef std::function<Box*(int, int, RewriterVar*&)> GetDefaultFunc;