Don't allocate memory inside an Assert() iff in a critical section.

HeapTupleHeaderGetCmax() asserts that it is only used if the tuple has
been updated by the current transaction. That check is correct and
sensible but requires allocating memory if xmax is a multixact. When
wal_level is set to logical cmax needs to be included in a wal record
, generated inside a critical section, which can trigger the assertion
added in 4a170ee9e.

Reported-By: Steve Singer
Allow total number of transactions in pgbench to exceed INT_MAX.

Change the total-transactions counters from int32 to int64 to accommodate
cases where we do more than 2^31 transactions during a run.  This patch
does not change the INT_MAX limit on explicit "-t" parameters, but it
does allow the product of the -t and -c parameters to exceed INT_MAX, or
allow a -T limit that is large enough that more than 2^31 transactions
can be completed.  While pgbench did not actually fail in such cases,
it did print an incorrect total-transactions count, and some of the
derived numbers such as TPS would have been wrong as well.

Tomas Vondra
Fix error when trying to delete page with half-dead left sibling.

The new page deletion code didn't cope with the case the target page's
right sibling was marked half-dead. It failed a sanity check which checked
that the downlinks in the parent page match the lower level, because a
half-dead page has no downlink. To cope, check for that condition, and
just give up on the deletion if it happens. The vacuum will finish the
deletion of the half-dead page when it gets there, and on the next vacuum
after that the empty can be deleted.

Reported by Jeff Janes.
Small typo and formatting fixes in postgresql.conf.sample
Fix pg_recvlogical to accept the documented -I instead only --startpos.

The bug was caused by omitting 'I:' from the short argument list to
getopt_long(). To make similar bugs in the future less likely reorder
options in --help, long and short option lists to be in the same,
alphabetical within groups, order.

Report and fix by Michael Paquier, some additional reordering by me.
Avoid unportable usage of sscanf(UINT64_FORMAT).

On Mingw, it seems that scanf() doesn't necessarily accept the same format
codes that printf() does, and in particular it may fail to recognize %llu
even though printf() does.  Since configure only probes printf() behavior
while setting up the INT64_FORMAT macros, this means it's unsafe to use
those macros with scanf().  We had only one instance of such a coding
pattern, in contrib/pg_stat_statements, so change that code to avoid
the problem.

Per buildfarm warnings.  Back-patch to 9.0 where the troublesome code
was introduced.

Michael Paquier
worker_spi: Initialize bgw_notify_pid in all cases.

Commit 090d0f2050647958865cb495dff74af7257d2bb4 added new code showing
how it can be useful to set bgw_notify_pid to a non-zero value, but it
failed to make sure that the existing call to RegisterBackgroundWorker
initialized the new field at all.

Report and patch by Shigeru Hanada.
merge master