swift234

[codecompletion] Add @escaping to override completions

Flush out the ASTPrinter's ability to exclude and include specific
attributes to cover TypeAttrKinds and have code-completion use this to
print @escaping in override completions.  Incidentally fix a case where
we weren't forwarding important options after type transformation, which
prevented printing @escaping in transformed parameter types.

rdar://problem/27772722