pgsql: Set pg_setting.pending_restart when pertinent config lines are r

Set pg_setting.pending_restart when pertinent config lines are removed

This changes the behavior of examining the pg_file_settings view after
changing a config option that requires restart. The user needs to know
that any change of such options does not take effect until a restart,
and this worked correctly if the line is edited without removing it.
However, for the case where the line is removed altogether, the flag
doesn't get set, because a flag was only set in set_config_option, but
that's not called for lines removed. Repair.

(Ref.: commits 62d16c7fc561 and a486e35706ea)

Author: Álvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
Reviewed-by: Daniel Gustafsson <daniel(at)yesql(dot)se>
Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Discussion: https://postgr.es/m/202107262302.xsfdfc5sb7sh@alvherre.pgsql

Branch
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REL9_6_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/85ec6c32265013ad2de145c3684fb026e094f0cb

Modified Files
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src/backend/utils/misc/guc-file.l | 2 ++
1 file changed, 2 insertions(+)