Implement parsing, AST, and conformance checking for associated types

in protocols, e.g.,

  protocol Range {
    typealias Element
    func getAndAdvance() -> Element
  }



Swift SVN r1941

lib/Parse/ParsePattern.cpp

@@ -39,6 +39,7 @@ bool Parser::checkFullyTyped(Type type) {
   case TypeKind::MetaType:
   case TypeKind::Module:
   case TypeKind::UnstructuredDependent:
+  case TypeKind::Archetype:
     return false;
 
   case TypeKind::Paren: