pgsql: process startup: Initialize PgStartTime earlier in single user m

process startup: Initialize PgStartTime earlier in single user mode.

An upcoming patch splits single user mode handling out of PostgresMain(). The
startup time only needs to be determined in single user mode. Currently the
initialization happens late, which makes the split a bit harder. As postmaster
determines the time earlier it makes sense to move the time for single user
mode to a roughly similar point in time.

Reviewd-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20210802164124.ufo5buo4apl6yuvs@alap3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/2c7615f77b8d84130d304365aa2235eea7b5949c

Modified Files
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src/backend/tcop/postgres.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)