Compiler [Typechecker]: Added PT_FLAG_CMP_FUN_ARG. This flag is intended to be used when handling attributes on types that expand to sequences, do that the handler can differentiate between matches like array(__attribute__("foo", mixed)) and function(__attribute__("foo", mixed)...: mixed) in the latter case PT_FLAG_CMP_FUN_ARG will be set, so that the handler can expand the attribute one argument at a time, and in the former case it will not be set, so that the types can be joined into a single type.