pgsql: Use InitFunctionCallInfoData() macro instead of MemSet in

Log Message:
-----------
Use InitFunctionCallInfoData() macro instead of MemSet in performance
critical places in execQual.  By Atsushi Ogawa; some minor cleanup by moi.

Modified Files:
--------------
    pgsql/src/backend/executor:
        execQual.c (r1.173 -> r1.174)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execQual.c.diff?r1=1.173&r2=1.174)
        nodeAgg.c (r1.130 -> r1.131)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeAgg.c.diff?r1=1.130&r2=1.131)
    pgsql/src/backend/utils/fmgr:
        fmgr.c (r1.89 -> r1.90)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/fmgr/fmgr.c.diff?r1=1.89&r2=1.90)
    pgsql/src/backend/utils/sort:
        tuplesort.c (r1.46 -> r1.47)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/sort/tuplesort.c.diff?r1=1.46&r2=1.47)
    pgsql/src/include:
        fmgr.h (r1.36 -> r1.37)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/fmgr.h.diff?r1=1.36&r2=1.37)