pgsql: Update Cygwin build to not use DLLINIT, per Cygwin report from

Log Message:
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Update Cygwin build to not use DLLINIT, per Cygwin report from Reini
Urban

Modified Files:
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pgsql/src:
Makefile.shlib (r1.81 -> r1.82)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/Makefile.shlib.diff?r1=1.81&r2=1.82)