pgsql: Fix for early log messages during postmaster startup getting lost

Log Message:
-----------
Fix for early log messages during postmaster startup getting lost when
running as a service on Win32.

Per report from Harald Armin Massa.

Backpatch to 8.1.

Tags:
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REL8_1_STABLE

Modified Files:
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pgsql/src/backend/postmaster:
postmaster.c (r1.475.2.6 -> r1.475.2.7)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/postmaster/postmaster.c.diff?r1=1.475.2.6&r2=1.475.2.7)
pgsql/src/backend/utils/error:
elog.c (r1.167.2.1 -> r1.167.2.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/error/elog.c.diff?r1=1.167.2.1&r2=1.167.2.2)