pgsql: Tweak recently-added tests to suppress scary-looking warnings on

Log Message:
-----------
Tweak recently-added tests to suppress scary-looking warnings on 64-bit
machines about casts between pointers and integers of different sizes.
While they're harmless, we shouldn't expect users to have to go through
and figure that out for themselves.

Modified Files:
--------------
    pgsql/src/interfaces/ecpg/test/expected:
        thread-alloc.c (r1.2 -> r1.3)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/thread-alloc.c?r1=1.2&r2=1.3)
        thread-prep.c (r1.3 -> r1.4)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/thread-prep.c?r1=1.3&r2=1.4)
        thread-thread.c (r1.16 -> r1.17)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/thread-thread.c?r1=1.16&r2=1.17)
        thread-thread_implicit.c (r1.16 -> r1.17)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/thread-thread_implicit.c?r1=1.16&r2=1.17)
    pgsql/src/interfaces/ecpg/test/thread:
        alloc.pgc (r1.2 -> r1.3)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/thread/alloc.pgc?r1=1.2&r2=1.3)
        prep.pgc (r1.3 -> r1.4)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/thread/prep.pgc?r1=1.3&r2=1.4)
        thread.pgc (r1.4 -> r1.5)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/thread/thread.pgc?r1=1.4&r2=1.5)
        thread_implicit.pgc (r1.4 -> r1.5)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/thread/thread_implicit.pgc?r1=1.4&r2=1.5)