This results in a more correct diagnostic being printed for closures with
capture lists, rather than claiming that they aren't literal closures.
Swift SVN r29058
This is new attribute we're using to coalesce @thin, @objc_block, and @cc, and to extend to new uses like C function pointer types. Parse the new attribute, but preserve support for the old attributes, and print with the old attributes for now to separate out test changes. Migration fixits and test updates to come. I did take the opportunity here to kill off the '@cc(cdecl)' hack for AST-level function pointer types, which are now only spelt with @convention(c).
Swift SVN r27247
Since a function pointer doesn't carry any context, we can only form a C function pointer from a static reference to a global function or a context-free local function or closure. (Or maybe a static function applied to its metatype, but that's not handled here yet.) As a placeholder for a to-be-bikeshedded surface syntax, let the existing @cc(cdecl) attribute appear in source text when the -enable-c-function-pointers frontend flag is passed.
Swift SVN r25308
