[COMMITTERS] pgsql: Fix bug in hashbulkdelete.

Fix bug in hashbulkdelete.

Commit 6d46f4783efe457f74816a75173eb23ed8930020 failed to account for
the possibility that hashbulkdelete() might encounter a bucket that
has been split since it began scanning the bucket array.  Repair.

Extracted from a larger pathc by Amit Kapila; I rewrote the comment.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/501c7b94bcb00cfa0faad60135cf6af82fd56a3a

Modified Files
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src/backend/access/hash/hash.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)