pgsql: Fix default minimum value for descending sequences

Fix default minimum value for descending sequences

For some reason that is lost in history, a descending sequence would
default its minimum value to -2^63+1 (-PG_INT64_MAX) instead of
-2^63 (PG_INT64_MIN), even though explicitly specifying a minimum value
of -2^63 would work. Fix this inconsistency by using the full range by
default.

Reported-by: Daniel Verite <daniel(at)manitou-mail(dot)org>
Reviewed-by: Michael Paquier <michael(dot)paquier(at)gmail(dot)com>

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/0bc1207aeb3de951bf95a9e9899b1256216d65f5

Modified Files
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doc/src/sgml/ref/create_sequence.sgml | 2 +-
src/backend/commands/sequence.c | 4 ++--
src/bin/pg_dump/pg_dump.c | 4 ++--
src/include/pg_config_manual.h | 6 ------
4 files changed, 5 insertions(+), 11 deletions(-)