Fixtype of declarations [C:6.7] [C:A.2.2].
This is a tagged union type, introduced by fty::deftagsum.
As a GCC extension, we also include a list of zero or more attribute specifiers as part of a declaration, meant to come after all the declarators. This is not fully general, but it covers a set of cases of interest. The list is empty if there are no attribute specifiers, e.g. when sticking to standard C without GCC extensions.
As a GCC extension,
we include the possibility that
the declaration starts with the