swift234

[Serialization] Try to avoid serializing the same Archetype in different modules

For BoundGenericType, we check if the generic arguments are Archetype and if the
Archetype appears in the Decl's Archetypes, if yes, we use indices into the
Decl's Archetypes instead of serializing the Archetype.

We add INT32_MAX as the first argument to notify the deserializer that the
arguments are indices into the Decl's Archetypes.

We also add a warning message when the Decl is serialized as a cross reference
and the generic arguments are serialized in this module.

rdar://16536656


Swift SVN r16424