Tests for CHECK/DEFAULT

src/test/regress/data/constrf.data

src/test/regress/data/constro.data

src/test/regress/expected/Makefile

src/test/regress/input/Makefile

src/test/regress/input/constraints.source

src/test/regress/output/Makefile

src/test/regress/output/constraints.source

src/test/regress/sql/Makefile

src/test/regress/sql/tests