Get the enumerator's enumeration type

Get the enumerator's enumeration type

Enumeration values are ultimately treated as constants but the path:
literal_stmt_for_local -> find_variable_and_frame_base (-> dwarf_get_enum)
-> translate_final_fetch_or_store often assume there is a
type die. Have dwarf_get_enum also get the type from the enumeration
type and percolate it along.