Source-side parser for CREATE TYPE x AS ENUM (...).
CREATE TYPE x AS ENUM (...)
Produces a UserType with kind = UserTypeKind::Enum { values }. Enum values receive sort_order 1.0, 2.0, 3.0, … matching PG’s pg_enum.enumsortorder semantics.
UserType
kind = UserTypeKind::Enum { values }
sort_order
pg_enum.enumsortorder