Need the _LIBCPP_NONUNIQUE_RTTI_BIT here, too

Doesn't help though, throwing exceptions using __cxa_throw() and our
hand-crafted type_infos still doesn't work on arm64.

Change-Id: If6099e8696e6232c4b6d4bacd654d28419538e0f
Add static assertion that our Fake_type_info is the same size as the real one

Change-Id: Id8490bb6373d85be2c529a005be55295c530febb