pgsql: Add support for loadable modules to allocated shared memory and

Log Message:
-----------
Add support for loadable modules to allocated shared memory and
lightweight locks.

Marc Munro

Modified Files:
--------------
pgsql/src/backend/storage/ipc:
ipci.c (r1.86 -> r1.87)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/ipci.c.diff?r1=1.86&r2=1.87)
shmem.c (r1.94 -> r1.95)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/shmem.c.diff?r1=1.94&r2=1.95)
pgsql/src/backend/storage/lmgr:
lwlock.c (r1.42 -> r1.43)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/lmgr/lwlock.c.diff?r1=1.42&r2=1.43)
pgsql/src/include/storage:
lwlock.h (r1.30 -> r1.31)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/lwlock.h.diff?r1=1.30&r2=1.31)
pg_shmem.h (r1.18 -> r1.19)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/pg_shmem.h.diff?r1=1.18&r2=1.19)
shmem.h (r1.47 -> r1.48)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/shmem.h.diff?r1=1.47&r2=1.48)