Bug 1189872 - Make {Map, Set}.prototype an ordinary object. r=Waldo

js/src/builtin/MapObject.cpp

@@ -267,10 +267,9 @@ InitClass(JSContext* cx, Handle<GlobalObject*> global, const Class* clasp, JSPro
           const JSPropertySpec* properties, const JSFunctionSpec* methods,
           const JSPropertySpec* staticProperties)
 {
-    RootedNativeObject proto(cx, global->createBlankPrototype(cx, clasp));
+    RootedPlainObject proto(cx, NewBuiltinClassInstance<PlainObject>(cx));
     if (!proto)
         return nullptr;
-    proto->setPrivate(nullptr);
 
     Rooted<JSFunction*> ctor(cx, global->createConstructor(cx, construct, ClassName(key, cx), 0));
     if (!ctor ||

js/src/jit-test/tests/collections/Map-surfaces-1.js

@@ -13,7 +13,11 @@ assertEq(Map.length, 0);
 assertEq(Map.name, "Map");
 
 assertEq(Object.getPrototypeOf(Map.prototype), Object.prototype);
-assertEq(Object.prototype.toString.call(Map.prototype), "[object Map]");
+assertEq("toStringTag" in Symbol, false,
+         "if this fails, congratulations!  implement " +
+         "Map.prototype[Symbol.toStringTag] = 'Map' in SpiderMonkey and make " +
+         "the next test check for '[object Map]' again");
+assertEq(Object.prototype.toString.call(Map.prototype), "[object Object]");
 assertEq(Object.prototype.toString.call(new Map()), "[object Map]");
 assertEq(Object.keys(Map.prototype).join(), "");
 assertEq(Map.prototype.constructor, Map);

js/src/jit-test/tests/collections/Set-surfaces-1.js

@@ -13,7 +13,11 @@ assertEq(Set.length, 0);
 assertEq(Set.name, "Set");
 
 assertEq(Object.getPrototypeOf(Set.prototype), Object.prototype);
-assertEq(Object.prototype.toString.call(Set.prototype), "[object Set]");
+assertEq("toStringTag" in Symbol, false,
+         "if this fails, congratulations!  implement " +
+         "Set.prototype[Symbol.toStringTag] = 'Set' in SpiderMonkey and make " +
+         "the next test check for '[object Set]' again");
+assertEq(Object.prototype.toString.call(Set.prototype), "[object Object]");
 assertEq(Object.prototype.toString.call(new Set()), "[object Set]");
 assertEq(Object.keys(Set.prototype).join(), "");
 assertEq(Set.prototype.constructor, Set);