pgsql: Split the shared-memory array of PGPROC pointers out of the

Log Message:
-----------
Split the shared-memory array of PGPROC pointers out of the sinval
communication structure, and make it its own module with its own lock.
This should reduce contention at least a little, and it definitely makes
the code seem cleaner. Per my recent proposal.

Modified Files:
--------------
pgsql/src/backend/access/heap:
heapam.c (r1.190 -> r1.191)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/heapam.c.diff?r1=1.190&r2=1.191)
pgsql/src/backend/access/transam:
README (r1.2 -> r1.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/README.diff?r1=1.2&r2=1.3)
multixact.c (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/multixact.c.diff?r1=1.3&r2=1.4)
subtrans.c (r1.7 -> r1.8)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/subtrans.c.diff?r1=1.7&r2=1.8)
varsup.c (r1.63 -> r1.64)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/varsup.c.diff?r1=1.63&r2=1.64)
xact.c (r1.200 -> r1.201)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c.diff?r1=1.200&r2=1.201)
xlog.c (r1.191 -> r1.192)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlog.c.diff?r1=1.191&r2=1.192)
pgsql/src/backend/catalog:
index.c (r1.255 -> r1.256)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/index.c.diff?r1=1.255&r2=1.256)
pgsql/src/backend/commands:
dbcommands.c (r1.156 -> r1.157)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/dbcommands.c.diff?r1=1.156&r2=1.157)
vacuum.c (r1.308 -> r1.309)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuum.c.diff?r1=1.308&r2=1.309)
vacuumlazy.c (r1.53 -> r1.54)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuumlazy.c.diff?r1=1.53&r2=1.54)
pgsql/src/backend/storage/buffer:
buf_init.c (r1.72 -> r1.73)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/buffer/buf_init.c.diff?r1=1.72&r2=1.73)
bufmgr.c (r1.188 -> r1.189)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/buffer/bufmgr.c.diff?r1=1.188&r2=1.189)
pgsql/src/backend/storage/ipc:
Makefile (r1.18 -> r1.19)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/Makefile.diff?r1=1.18&r2=1.19)
ipci.c (r1.75 -> r1.76)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/ipci.c.diff?r1=1.75&r2=1.76)
sinval.c (r1.75 -> r1.76)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/sinval.c.diff?r1=1.75&r2=1.76)
sinvaladt.c (r1.58 -> r1.59)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/sinvaladt.c.diff?r1=1.58&r2=1.59)
pgsql/src/backend/storage/lmgr:
lmgr.c (r1.73 -> r1.74)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/lmgr/lmgr.c.diff?r1=1.73&r2=1.74)
proc.c (r1.157 -> r1.158)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/lmgr/proc.c.diff?r1=1.157&r2=1.158)
pgsql/src/backend/utils/adt:
misc.c (r1.42 -> r1.43)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/misc.c.diff?r1=1.42&r2=1.43)
pgsql/src/backend/utils/init:
postinit.c (r1.146 -> r1.147)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/postinit.c.diff?r1=1.146&r2=1.147)
pgsql/src/backend/utils/time:
tqual.c (r1.88 -> r1.89)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/time/tqual.c.diff?r1=1.88&r2=1.89)
pgsql/src/include/storage:
buf_internals.h (r1.77 -> r1.78)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/buf_internals.h.diff?r1=1.77&r2=1.78)
lwlock.h (r1.18 -> r1.19)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/lwlock.h.diff?r1=1.18&r2=1.19)
proc.h (r1.77 -> r1.78)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/proc.h.diff?r1=1.77&r2=1.78)
sinval.h (r1.40 -> r1.41)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/sinval.h.diff?r1=1.40&r2=1.41)
sinvaladt.h (r1.37 -> r1.38)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/sinvaladt.h.diff?r1=1.37&r2=1.38)
pgsql/src/include/utils:
tqual.h (r1.56 -> r1.57)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/tqual.h.diff?r1=1.56&r2=1.57)

Added Files:
-----------
pgsql/src/backend/storage/ipc:
procarray.c (r1.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/procarray.c?rev=1.1&content-type=text/x-cvsweb-markup)
pgsql/src/include/storage:
procarray.h (r1.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/procarray.h?rev=1.1&content-type=text/x-cvsweb-markup)