Most of this patch is just removing special cases for materializeForSet
or other fairly mechanical replacements. Unfortunately, the rest is
still a fairly big change, and not one that can be easily split apart
because of the quite reasonable reliance on metaprogramming throughout
the compiler. And, of course, there are a bunch of test updates that
have to be sync'ed with the actual change to code-generation.
This is SR-7134.
Follow-up for 7c707ce97c. Without this, the declaration would be
accepted, but any uses of the overridden property would be treated as
ambiguous because the property wouldn't really be marked as an
override.
rdar://problem/35900345
