Bug 1516473. Remove the compartment assert from GetObjectClassName. r=jandem

This is the one thing preventing use of a js::Wrapper for a proxy handler that
forwards all ops to a wrapped proxy without entering its compartment.  None of
the other ops at this level do compartment asserts.

Callers of this function other than ForwardingProxyHandler do their own asserts
already.

js/src/vm/JSObject-inl.h

@@ -605,8 +605,6 @@ extern NativeObject* InitClass(JSContext* cx, HandleObject obj,
 
 MOZ_ALWAYS_INLINE const char* GetObjectClassName(JSContext* cx,
                                                  HandleObject obj) {
-  cx->check(obj);
-
   if (obj->is<ProxyObject>()) {
     return Proxy::className(cx, obj);
   }