pgsql: Change MemSet to use long instead of int32, for better

Log Message:
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Change MemSet to use long instead of int32, for better performance on
64-bit platforms.

by ITAGAKI Takahiro

Modified Files:
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pgsql/src/include:
c.h (r1.195 -> r1.196)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/c.h.diff?r1=1.195&r2=1.196)