swift234

ClangImporter: Enable import of objc protocol types.

Remove the -import-objc-protocol-types flag and make it the default behavior. Update swiftFoundation's NSDictionary extensions to use NSCopyingProto keys instead of plain id.

This breaks a test because the type-checker isn't able to solve for NSCopyingProto from a literal type, requiring a manual 'as NSNumber/NSString' coercion to help it along.

Swift SVN r5641