Validate a direct abstract declarator.
(valid-dirabsdeclor dirabsdeclor type table ienv) → (mv erp new-dirabsdeclor new-type return-types new-table)
This is fairly similar to valid-dirdeclor (see that function's documentation), but since the direct declarator is abstract, there is no identifier being declared to return. Furthermore, there is no flag for function definitions, since a function definition uses a (direct) declarator, not an (direct) abstract declarator.