pgsql: Casts to or from a domain type are ignored; warn and document.

Casts to or from a domain type are ignored; warn and document.

Prohibiting this outright would break dumps taken from older versions
that contain such casts, which would create far more pain than is
justified here.

Per report by Jaime Casanova and subsequent discussion.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/3ce7f18e92e9687308ed5d9e516eb7e2f0decadb

Modified Files
--------------
doc/src/sgml/ref/create_cast.sgml        |    5 +++++
src/backend/commands/functioncmds.c      |   11 +++++++++++
src/test/regress/expected/privileges.out |    1 +
3 files changed, 17 insertions(+), 0 deletions(-)