Add support for Oracle 23ai's DDL DOMAIN type reference syntax <base-type> DOMAIN <domain-name>

[lukaseder]

This is legal syntax in Oracle:

create domain x as int;
create table t (x int domain x); -- Explicit syntax here

The purpose is probably to override the domain's base type, e.g.

create domain x as number(3);
create table t (x number(4) domain x);

It's not unlikely that other RDBMS also support such a syntax, given that a domain can be used also to inherit CHECK constraints.