HEADS-UP Initial DTrace port added to current

[Darran Hunt <darran%NetBSD.org@localhost>]

Courtesy of CoyotePoint Systems, I've committed a port of DTrace (http://en.wikipedia.org/wiki/DTrace 
) to NetBSD current for i386. The port is based on the FreeBSD-8 port.
DTrace is a dynamic tracing framework developed by Sun. It enables the  
instrumentation of the kernel and user space and provides powerful  
debugging and inspection options via tracing scripts. See http://wikis.sun.com/display/DTrace/Introduction 
 for an introduction.

See http://wiki.netbsd.se/How_to_enable_and_run_DTrace for details on  
trying out a hello world script.

At the moment the DTrace kernel module builds and loads, and its able  
to execute a basic hello world D script using the built-in BEGIN/END  
provider. It still needs work to support kernel modules, user- space  
tracing (via libproc), providers (fbt, sdt, systrace, profiler,  
lockstat, etc), and a few other bit and pieces marked with "XXX  
TBD"comments in the code. It doesn't do much at the moment but once  
providers are completed DTrace will enable interesting views into the  
kernel for inspection and profiling, and debugging.  It may be a bit  
unstable - please let me know if you run into any problems trying it  
out.

I'm working on an SDT provider as an example provider and should have  
that committed next week.

Regards,
Darran.