[RFC]: Remote Protocol "attach" command.

[Michael Snyder]

More and more embedded operating systems are multi-process
these days, and so there exists a need to have a stub or a
gdbserver already running (perhaps all the time), and have it
"attach" to another running process and debug it.  For native
Unix systems, this has traditionally been done by running 
gdbserver from a shell, giving it the path to the executable,
and letting it fork the new process.

I'd like to start a discussion about adding a new remote
protocol command with which GDB could ask the remote stub
to attach to a running process (by pid), or possibly to
open a file and fork a process (by filename/path).  Of course,
stubs that can't do that would simply return an empty reply
as always, indicating non-compliance.

Thoughts?

Michael