swift234

[CodeComplete] Refine the code completion results for unresolved members by using constraint solver.
Before this commit, for unresolved members, code completion suggests all visible enum elements
 and option set types. To refine the results, this commit uses constraint solver to infer
the type of unresolved members by analyzing parental expressions. If the solver has solutions,
we complete the unresolved member, otherwise abort.
rdar://16659653

Swift SVN r31195