swift234

Fix <rdar://problem/16797372> Bogus error: self.init called multiple times in initializer

DI has two paths for analyzing initialization state: one optimize for solving a single
fact (e.g. the state of a single non-tuple variable in a function), and one that handles 
the full generality of multiple states in parallel (e.g. a tuple in a function or the
fields of a struct/class during its init method).

Unfortunately, the dataflow analysis between these two implementations drifted, and I
fixed a bug in the "N" case (rdar://16119509 back in feb) that didn't get fixed in the "1"
case.  This reworks all of the dataflow to make the fact propagation more similar between
the two paths and fix the bug along the way.



Swift SVN r17343