pgsql: Add %expect 0 to all parser input files to prevent conflicts

Log Message:
-----------
Add %expect 0 to all parser input files to prevent conflicts slipping by.

Modified Files:
--------------
    pgsql/contrib/cube:
        cubeparse.y (r1.18 -> r1.19)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/contrib/cube/cubeparse.y?r1=1.18&r2=1.19)
    pgsql/contrib/seg:
        segparse.y (r1.18 -> r1.19)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/contrib/seg/segparse.y?r1=1.18&r2=1.19)
    pgsql/src/backend/bootstrap:
        bootparse.y (r1.94 -> r1.95)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootparse.y?r1=1.94&r2=1.95)
    pgsql/src/backend/parser:
        gram.y (r2.640 -> r2.641)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y?r1=2.640&r2=2.641)
    pgsql/src/interfaces/ecpg/preproc:
        ecpg.header (r1.2 -> r1.3)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/ecpg.header?r1=1.2&r2=1.3)
    pgsql/src/pl/plpgsql/src:
        gram.y (r1.116 -> r1.117)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/gram.y?r1=1.116&r2=1.117)