When we check a protocol conformance, we recurse to check the implied
protocol conformances for inherited protocols first. When doing so, we
were passing down the current DeclContext, which would force the
creation of a new conformance to that protocol within that
DeclContext. This isn't what we want: we want to find or create the
conformance in whichever context it naturally belongs.
This is a partial step toward solving the problem, which eliminates
the duplicate witness tables from the example in
rdar://problem/18182969. However, we're still not using the
conformance lookup table to decide where the witness tables/protocol
conformances go, which means the actual declaration context for a
witness table is still a bit ad hoc.
Baby steps.
Swift SVN r26129
When code completing a literal expr, it is likely that code completion engine only collects the expr
that is not fully type checked. Therefore, no members of the literal can be suggested. To address this,
we try to climb up expr hierarchy in AST to find an expr with a nominal type, and use the nominal type
to finish code completion.
rdar://20059173
Swift SVN r26116
