pgsql-server: Reduce the minimum allocable chunk size to 8 bytes (from - Mailing list pgsql-committers

Log Message:
-----------
Reduce the minimum allocable chunk size to 8 bytes (from 16).  Now that
ListCells are only 8 bytes instead of 12 (on 4-byte-pointer machines
anyway), it's worth maintaining a separate freelist for 8-byte objects.
Remembering that alloc chunks carry 8 bytes of overhead, this should
reduce the net storage requirement for a long List by about a third.

Modified Files:
--------------
    pgsql-server/src/backend/utils/mmgr:
        aset.c (r1.54 -> r1.55)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/mmgr/aset.c.diff?r1=1.54&r2=1.55)