Bug 537873: Add a 'strict' argument to C++ property setter functions. r=brendan

This changes the type of setters to JSStrictPropertyOp, which is just like
JSPropertyOp except that it takes a 'JSBool strict' argument. Most of the
patch is introducing distinct types and using the appropriate stubs.

The following are left for subsequent patches:

x Similar fixes to the browser outside SpiderMonkey.

x Actually *using* the newly available strictness information. This patch
  should have no user-visible effect. I didn't want the interesting stuff
  to get lost in this noise.

js/src/jsdate.cpp

@@ -493,10 +493,10 @@ Class js_DateClass = {
     js_Date_str,
     JSCLASS_HAS_RESERVED_SLOTS(JSObject::DATE_CLASS_RESERVED_SLOTS) |
     JSCLASS_HAS_CACHED_PROTO(JSProto_Date),
-    PropertyStub,   /* addProperty */
-    PropertyStub,   /* delProperty */
-    PropertyStub,   /* getProperty */
-    PropertyStub,   /* setProperty */
+    PropertyStub,         /* addProperty */
+    PropertyStub,         /* delProperty */
+    PropertyStub,         /* getProperty */
+    StrictPropertyStub,   /* setProperty */
     EnumerateStub,
     ResolveStub,
     ConvertStub
@@ -2599,7 +2599,7 @@ js_InitDateClass(JSContext *cx, JSObject *obj)
     jsid toGMTStringId = ATOM_TO_JSID(cx->runtime->atomState.toGMTStringAtom);
     if (!js_GetProperty(cx, proto, toUTCStringId, toUTCStringFun.addr()) ||
         !js_DefineProperty(cx, proto, toGMTStringId, toUTCStringFun.addr(),
-                           PropertyStub, PropertyStub, 0)) {
+                           PropertyStub, StrictPropertyStub, 0)) {
         return NULL;
     }