pgsql: Share RI trigger code between NO ACTION and RESTRICT cases.

Share RI trigger code between NO ACTION and RESTRICT cases.

These triggers are identical except for whether ri_Check_Pk_Match is to be
called, so factor out the common code to save a couple hundred lines.

Also, eliminate null-column checks in ri_Check_Pk_Match, since they're
duplicate with the calling functions and require unnecessary complication
in its API statement.

Simplify the way code is shared between RI_FKey_check_ins and
RI_FKey_check_upd, too.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/fe3db740025d80f70ceccb33b2bf3c085a2fca80

Modified Files
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src/backend/utils/adt/ri_triggers.c | 778 +++++++++--------------------
src/test/regress/expected/foreign_key.out | 26 +
src/test/regress/sql/foreign_key.sql | 22 +
3 files changed, 282 insertions(+), 544 deletions(-)