swift234

[serialization] Record nominal types in the module table ASAP.

Deserializing a nominal decl often ends up referring to the nominal's type,
so if we're /already/ serializing the type, we should finish that as soon
as we have a decl. Accomplish this by adding a callback that is called
right after a nominal decl is recorded in the module's decl table, so that
the type can be immediately recorded as well.

Swift SVN r6227