SILGen eagerly produces witness tables for all of the conformances defined in the module, which is what we want in order to make them runtime-unique. Have IRGen follow suit. This should address a ton of radars about breakage with non-unique conformances once SIL witnesses are turned on. We will need some runtime machinery to handle witness tables with dependent fields, but since we currently ignore the associated type fields of witnesses, we can get away with emitting direct references to all witness tables for now.
Swift SVN r11608
We'll need to perform name lookup based on the file-level
DeclContext*, so the module no longer suffices. No functionality
change here yet.
Swift SVN r11523
This is a structural baby step toward lazily filling in protocol
conformances. We always build a ProtocolConformance, then mark it
either "complete" (when it's well-formed) or "invalid" (when it's
ill-formed). At present, the only benefit to this is that it slows
diagnostic cascades from invalid conformances.
Swift SVN r11492
A SpecializedProtocolConformance intentionally contains all of the
information we need to synthesize the type witnesses from the
underlying (generic) conformance. Do so lazily rather than eagerly,
because we won't always need all of them.
As a nice side effect, we no longer need to serialize the witnesses of
these specialized protocol conformances, so we can save some space in
the Swift module file.
Swift SVN r11303
It's useful to know what the open type variables in a generic protocol conformance are. For now, make the somewhat shaky assumptions that a NormalProtocolConformance for a bound generic type is for the DeclaredTypeInContext of its originating nominal type, that all type variables of the nominal type are open, and that specialized and inherited conformances bind all of the generic parameters.
Swift SVN r11274
