import changes from rmottola/Arctic-Fox:

- Bug 1131805 part 1. Remove remaining JS_GetParent and js::GetObjectParent uses in Gecko. (5ec206e98)
- Bug 1137578. Remove JS_GetParent usage from mozJSSubscriptLoader. (ba8b18d88)
- Bug 1131802 part 1. Add JS friend API to test whether a given function object has extended slots. (d7a2bad97)
- Bug 1131802 part 2. Allocate functions with reserved slots for DOM Xrays so we can store the Xray wrapper reference in those slots instead of as the function parent. (7bc6dba71)
- Bug 1140399. Add friend API to check whether a given function object has a JSNative and to get that JSNative as needed. (71f0ccff7)
- Bug 1137334. Remove nsIDOMWindowUtils.getParent. (aa3de0a27)
- Bug 1125784 - Remove JS_ConvertArguments and JS_ConvertValue. (db6a1bd29)
- Bug 1137325. Remove the parent() function from xpcshell. (7cac0999e)
- Bug 1131797 part 1. Store an index into its XPCNativeInterface mMembers array in each XPCNativeMember. (2389614e2)
- Bug 1131797 part 2. Stop storing the XPCNativeInterface* in XPConnect function objects and just get it from the XPCNativeMember* we're still storing. (252172d87)
- Bug 1131797 part 3. Store the object we originally come from in a reserved slot on XPConnect functions instead of using the parent pointer. (252bb312f)
and fix requireAtLeast prototype for --enable-shared-js

xpcom/base/CycleCollectedJSRuntime.cpp

@@ -983,7 +983,7 @@ CycleCollectedJSRuntime::UsefulToMergeZones() const
     MOZ_ASSERT(js::IsOuterObject(obj));
     // Grab the inner from the outer.
     obj = JS_ObjectToInnerObject(cx, obj);
-    MOZ_ASSERT(!js::GetObjectParent(obj));
+    MOZ_ASSERT(JS_IsGlobalObject(obj));
     if (JS::ObjectIsMarkedGray(obj) &&
         !js::IsSystemCompartment(js::GetObjectCompartment(obj))) {
       return true;