pgsql: Add chklocale.c to pgport files for msvc builds, per buildfarm

Log Message:
-----------
Add chklocale.c to pgport files for msvc builds, per
buildfarm failures.

Modified Files:
--------------
pgsql/src/tools/msvc:
Mkvcbuild.pm (r1.17 -> r1.18)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/msvc/Mkvcbuild.pm?r1=1.17&r2=1.18)