Current CodeGeneratorV8 tries to create a hidden reference for a readonly Date attribute, but this makes compilation fail. Date is represented as a double (or v8::Date) and is not a RefPtr type, so I think we shouldn't generate the hidden reference code for Date.
Created attachment 64289 [details] Patch
I don't fully understand the code but I think it needs to go around the if statement around line 778 for Date (as we talked on chat). Can you take a look at the patch?
Seems related to jam magic.
Sorry, John. Turns out its not.
Comment on attachment 64289 [details] Patch ok.
Committed r66642: <http://trac.webkit.org/changeset/66642>