[RFA] mixed source+assembly from cli disassemble

[Joel Brobecker]

> Going on a week...
> No other comments, pro or con?

I really like the idea, it's something that I often wished we'd have
(and often asked for in graphical front-ends). I was going to review
the patch, but wanted to ask others to comment on the user interface
first. Once we agree on the syntax, then I can review the patch itself.

Doug suggests to use an optional "/s" modifier. For instance:

   (gdb) disassemble ADDR     -> regular assembly listing
   (gdb) disassemble /s ADDR  -> intermixed source+assembly listing

Is that OK with everyone? It's pretty consistent with what we do
for the print command, so I like it.

-- 
Joel