pgsql: Add: > > * Allow the size of the buffer cache used by temporary

Log Message:
-----------
Add:

* Allow the size of the buffer cache used by temporary objects to be
specified as a GUC variable

Larger local buffer cache sizes requires more efficient handling of
local cache lookups.

Modified Files:
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pgsql/doc:
TODO (r1.1419 -> r1.1420)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1419&r2=1.1420)