Disambiguate an enumeration specifier.
(dimb-enumspec enumspec table) → (mv erp new-enumspec new-table)
This also extends the disambiguation table with the names of the enumerators (i.e. enumeration constants). The scope of an enumeration constant starts just after the appearance of its enumerator [C:6.2.1/7]. The extension of the table is actually done by the function that disambiguates the enumerators.