swift234

Sema: Pass DeclContexts down into expression type-checking.

Thread the current DeclContext down into expression type-checking so that we will be able to set up ImplicitClosureExprs with the right parent context. (Don't actually set the right decl context when creating an ImplicitClosureExpr yet, since IRGen isn't quite ready to handle specialized partial applications and crashes on the emitted SIL if we do.)

Swift SVN r5431