pgsql: Enable probes to work with Mac OS X Leopard and other OSes that

Log Message:
-----------
Enable probes to work with Mac OS X Leopard and other OSes that will
support DTrace in the future.

Switch from using DTRACE_PROBEn macros to the dynamically generated macros.
Use "dtrace -h" to create a header file that contains the dynamically
generated macros to be used in the source code instead of the DTRACE_PROBEn
macros.  A dummy header file is generated for builds without DTrace support.

Author: Robert Lor <Robert.Lor@sun.com>

Modified Files:
--------------
    pgsql/src/backend:
        Makefile (r1.127 -> r1.128)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/Makefile?r1=1.127&r2=1.128)
    pgsql/src/backend/access/transam:
        xact.c (r1.259 -> r1.260)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.259&r2=1.260)
    pgsql/src/backend/storage/lmgr:
        lock.c (r1.182 -> r1.183)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/lmgr/lock.c?r1=1.182&r2=1.183)
        lwlock.c (r1.50 -> r1.51)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/lmgr/lwlock.c?r1=1.50&r2=1.51)
    pgsql/src/backend/utils:
        Makefile (r1.26 -> r1.27)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/Makefile?r1=1.26&r2=1.27)
    pgsql/src/include:
        Makefile (r1.23 -> r1.24)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/Makefile?r1=1.23&r2=1.24)
        c.h (r1.223 -> r1.224)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/c.h?r1=1.223&r2=1.224)
        pg_trace.h (r1.3 -> r1.4)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/pg_trace.h?r1=1.3&r2=1.4)

Added Files:
-----------
    pgsql/src/backend/utils:
        Gen_dummy_probes.sed (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/Gen_dummy_probes.sed?rev=1.1&content-type=text/x-cvsweb-markup)