pgsql: Fast promote mode skips checkpoint at end of recovery.

Fast promote mode skips checkpoint at end of recovery.
pg_ctl promote -m fast will skip the checkpoint at end of recovery so that we
can achieve very fast failover when the apply delay is low. Write new WAL record
XLOG_END_OF_RECOVERY to allow us to switch timeline correctly for downstream log
readers. If we skip synchronous end of recovery checkpoint we request a normal
spread checkpoint so that the window of re-recovery is low.

Simon Riggs and Kyotaro Horiguchi, with input from Fujii Masao.
Review by Heikki Linnakangas

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/fd4ced5230162b50a5c9d33b4bf9cfb1231aa62e

Modified Files
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src/backend/access/rmgrdesc/xlogdesc.c | 10 ++
src/backend/access/transam/xlog.c | 192 +++++++++++++++++++++++++++-----
src/bin/pg_ctl/pg_ctl.c | 18 +++-
src/include/access/xlog_internal.h | 6 +
src/include/catalog/pg_control.h | 1 +
5 files changed, 195 insertions(+), 32 deletions(-)