Capture complete associated type substitution information in the AST.

Previously, we only tracked the mapping from associated types to their
type witnesses. Now, also track the protocol conformances for each of
the requirements placed on the associated types.


Swift SVN r6655

lib/Serialization/ModuleFormat.h

@@ -369,7 +369,8 @@ namespace decls_block {
   using BoundGenericSubstitutionLayout = BCRecordLayout<
     BOUND_GENERIC_SUBSTITUTION,
     TypeIDField, // archetype
-    TypeIDField // replacement
+    TypeIDField, // replacement
+    BCVBR<6>     // # of conformances
     // Trailed by the protocol conformance info (if any)
   >;