swift234

With the previous fix, all of the tests from:
https://twitter.com/practicalswift/status/625429628107255808?refsrc=email&s=11

all compile without crashing, other than "()=()", which is tracked by:
<rdar://problem/21886435> Swift compiler crashes on "()=()"

This one crashes because "()" isn't being type checked as an lvalue.  If someone
feels inspired to fix this, it is our shortest known compiler crash.



Swift SVN r30735