Remove wrong assert to fix a debug crash with arguments object.

We don't need to assert the existence of a length-property of the
arguments object because it is not a JSArray, but just a normal JSObject.

BUG=v8:1227
Review URL: http://codereview.chromium.org/7064020

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8024 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/contexts.cc

@@ -162,7 +162,6 @@ Handle<Object> Context::Lookup(Handle<String> name, ContextLookupFlags flags,
         ASSERT(index >= 0);  // arguments must exist and be in the heap context
         Handle<JSObject> arguments(JSObject::cast(context->get(index)),
                                    isolate);
-        ASSERT(arguments->HasLocalProperty(isolate->heap()->length_symbol()));
         if (FLAG_trace_contexts) {
           PrintF("=> found parameter %d in arguments object\n", param_index);
         }