When we find that some type is used, remember to traverse into both that type's attributes as well as any attributes given when the underlying enum or structure tag was first declared.  Some of those attributes might use types as well, so we need to pick those up. Otherwise, it is possible to end up with, e.g., an "alignof" attribute that refers to a structure which has itself been removed as unused.
When we find that some type is used, remember to traverse into both
that type's attributes as well as any attributes given when the
underlying enum or structure tag was first declared.  Some of those
attributes might use types as well, so we need to pick those up.
Otherwise, it is possible to end up with, e.g., an "alignof" attribute
that refers to a structure which has itself been removed as unused.

samuelhavron/obliv-c,samuelhavron/obliv-c,samuelhavron/obliv-c,samuelhavron/obliv-c