Added a core :class:`Values` object that enables a VALUES construct
to be used in the FROM clause of an SQL statement for databases that
support it (mainly PostgreSQL and SQL Server).
Fixes: #4868Closes: #5030
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5030
Pull-request-sha: 84684038a8
Change-Id: Ib8109b63bc1a9dc04ab987c5322ca3375f7e824d