Whenever we visit a declaration via the DeclChecker, add it to the
list of declarations to finalize. This makes sure that we can centralize
the notion of “finalize for SILGen” and that it will be called for
everything in the source file being processed.
Implement code completion support for Objective-C #keyPath
expressions, using semantic analysis of the partially-typed keypath
argument to provide an appropriate set of results (i.e., just
properties and types).
This implements all of the necessary parts of SE-0062 / SR-1237 /
rdar://problem/25710611, although at some point I'd like to follow it
up with some warnings to help migrate existing string literals to
