pgsql: Never crash-and-restart for bgworkers without shared memory acce

Never crash-and-restart for bgworkers without shared memory access.

The motivation for a crash and restart cycle when a backend dies is
that it might have corrupted shared memory on the way down; and we
can't recover reliably except by reinitializing everything. But that
doesn't apply to processes that don't touch shared memory. Currently,
there's nothing to prevent a background worker that doesn't request
shared memory access from touching shared memory anyway, but that's a
separate bug.

Previous to this commit, the coding in postmaster.c was inconsistent:
an exit status other than 0 or 1 didn't provoke a crash-and-restart,
but failure to release the postmaster child slot did. This change
makes those cases consistent.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/e2ce9aa27bf20eff2d991d0267a15ea5f7024cd7

Modified Files
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src/backend/postmaster/postmaster.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)