pgsql: enable examples to compile on Windows.

Log Message:
-----------
enable examples to compile on Windows. patch from Hiroshi Saito.

Modified Files:
--------------
pgsql/src/test/examples:
Makefile (r1.14 -> r1.15)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/examples/Makefile?r1=1.14&r2=1.15)
testlibpq2.c (r1.15 -> r1.16)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/examples/testlibpq2.c?r1=1.15&r2=1.16)
testlibpq3.c (r1.16 -> r1.17)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/examples/testlibpq3.c?r1=1.16&r2=1.17)