pgsql: Add ALTER DOMAIN ... RENAME

Add ALTER DOMAIN ... RENAME

You could already rename domains using ALTER TYPE, but with this new
command it is more consistent with how other commands treat domains as
a subcategory of types.

Branch
------
master

Details
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http://git.postgresql.org/pg/commitdiff/f90dd28062db2128a340fbe02f55829f15ab5561

Modified Files
--------------
doc/src/sgml/ref/alter_domain.sgml   |   22 +++++++++++++++++++++-
src/backend/commands/alter.c         |    3 ++-
src/backend/commands/typecmds.c      |   11 ++++++++++-
src/backend/parser/gram.y            |    8 ++++++++
src/include/commands/typecmds.h      |    2 +-
src/test/regress/expected/domain.out |    7 +++++++
src/test/regress/sql/domain.sql      |   10 ++++++++++
7 files changed, 59 insertions(+), 4 deletions(-)