pgsql: Fixes for single-page hash index vacuum.

Fixes for single-page hash index vacuum.

Clear LH_PAGE_HAS_DEAD_TUPLES during replay, similar to what gets done
for btree. Update hashdesc.c for xl_hash_vacuum_one_page.

Oversights in commit 6977b8b7f4dfb40896ff5e2175cad7fdbda862eb spotted
by Amit Kapila. Patch by Ashutosh Sharma.

Bump WAL version. The original patch to make hash indexes write-ahead
logged probably should have done this, and the single page vacuuming
patch probably should have done it again, but better late than never.

Discussion: http://postgr.es/m/CAA4eK1Kd=mJ9xreovcsh0qMiAj-QqCphHVQ_Lfau1DR9oVjASQ@mail.gmail.com

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/953477ca3526e28f9aeeb41d23b16eed0084c7d2

Modified Files
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src/backend/access/hash/hash.c | 7 ++++++-
src/backend/access/hash/hash_xlog.c | 21 +++++++++++++++++++++
src/backend/access/hash/hashinsert.c | 8 ++++++++
src/backend/access/rmgrdesc/hashdesc.c | 11 ++++++++++-
src/include/access/hash_xlog.h | 2 ++
src/include/access/xlog_internal.h | 2 +-
6 files changed, 48 insertions(+), 3 deletions(-)