MSVC: Accept tcl86.lib in addition to tcl86t.lib.
MSVC: Accept tcl86.lib in addition to tcl86t.lib.

ActiveTcl8.6.4.1.299124-win32-x86_64-threaded.exe ships just tcl86.lib.
Back-patch to 9.2, like the commit recognizing tcl86t.lib.

adam8157/gpdb,ashwinstar/gpdb,adam8157/gpdb,xinzweb/gpdb,xinzweb/gpdb,lisakowen/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,50wu/gpdb,50wu/gpdb,jmcatamney/gpdb,adam8157/gpdb,jmcatamney/gpdb,50wu/gpdb,adam8157/gpdb,lisakowen/gpdb,lisakowen/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,lisakowen/gpdb,ashwinstar/gpdb,xinzweb/gpdb,50wu/gpdb,50wu/gpdb,greenplum-db/gpdb,lisakowen/gpdb,lisakowen/gpdb,lisakowen/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,lisakowen/gpdb,xinzweb/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,xinzweb/gpdb,xinzweb/gpdb,ashwinstar/gpdb,50wu/gpdb,50wu/gpdb,50wu/gpdb,adam8157/gpdb,jmcatamney/gpdb,adam8157/gpdb,xinzweb/gpdb,adam8157/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,adam8157/gpdb,xinzweb/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,greenplum-db/gpdb