DTrace probe patch for OS X Leopard

Please find the patch attached per this thread
http://archives.postgresql.org/pgsql-hackers/2008-02/msg00912.php

Notes to committer.

1) Please remove src/include/pg_trace.h as it's no longer needed

2) Need help figuring out how to copy src/backend/util/probes.d from src
tree to
bld tree at build time. It works fine if compilation is done in the src
tree.

3) Note on src/backend/Makefile
The current rule below does not work. After expansion, utils/probes.d
needs
to come right after -s, but currently it shows up at the end after
all the .o files.

utils/probes.o: utils/probes.d $(SUBDIROBJS)
$(DTRACE) $(DTRACEFLAGS) -G -s $(call expand_subsys,$^) -o $@

The following works, but I think the correct way is to include
probes.d as a
dependency and have it show up after -s. I couldn't get it to work
this way with
my somewhat limited knowledge of makefiles.

utils/probes.o: $(SUBDIROBJS)
$(DTRACE) $(DTRACEFLAGS) -G -s $(srcdir)/utils/probes.d -o $@
$(call expand_subsys,$^)

Regards,
-Robert