pgsql: Fix BRIN minmax-multi distance calculation for OID

Fix BRIN minmax-multi distance calculation for OID

The oid_minmax_multi_ops opclass simply calculated the distance using
brin_minmax_multi_distance_int4. That however interprets the values as
int32, so OIDs above PG_INT32_MAX were treated as negative values, and
ranges crossing the boundary ended with a negative distance.

With assert-enabled guild, this tripped the (a1 <= a2) check. Without
asserts, the index was less efficient.

Fix by introducing brin_minmax_multi_distance_oid, correctly treating
the OID values as unsigned.

This required a catalog change (and catversion bump), so it can't be
backpatched. It'd be possible to adjust brin_minmax_multi_distance_int4
to handle the (a1 > a2) case differently. But that'd lose the assert,
and it does not seem worth it (indexes on OIDs don't seem very common).

Author: Tomas Vondra <tomas(at)vondra(dot)me>
Reviewed-by: Kirill Reshke <reshkekirill(at)gmail(dot)com>
Reviewed-by: shihao zhong <zhong950419(at)gmail(dot)com>
Discussion: https://postgr.es/m/CALdSSPgBvXz-VSF0p-5k%3D_uFfN38cWrERmm_AC4K67N6MWQhmg%40mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4b6735c21fa4c43be041c6c610d7be6463c2c1f9

Modified Files
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src/backend/access/brin/brin_minmax_multi.c | 21 +++++++++++++++++++++
src/include/catalog/pg_amproc.dat | 2 +-
src/include/catalog/pg_proc.dat | 4 ++++
src/test/regress/expected/brin_multi.out | 5 +++++
src/test/regress/sql/brin_multi.sql | 8 ++++++++
5 files changed, 39 insertions(+), 1 deletion(-)