Thread: pgsql: Report success when Windows kill() emulation signals an exiting

Report success when Windows kill() emulation signals an exiting process.

This is consistent with the POSIX verdict that kill() shall not report
ESRCH for a zombie process.  Back-patch to 9.0 (all supported versions).
Test code from commit d7cdf6ee36adeac9233678fb8f2a112e6678a770 depends
on it, and log messages about kill() reporting "Invalid argument" will
cease to appear for this not-unexpected condition.

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/748da01d392f120c02460838a015cdd8193ed397

Modified Files
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src/port/kill.c |   29 ++++++++++++++++++++++-------
1 file changed, 22 insertions(+), 7 deletions(-)