Explicit Linespecs Branch Created

[Tom Tromey]

Keith> IOW, I am/was trying to avoid implementing backend gdb APIs in terms
Keith> of the command line.

I see.  Well, that does make sense.  It just seems like it will be hard
to use from the CLI.

Tom> How hard is it to add support for this to other linespec-using
Tom> commands?

Keith> That all depends on the UI. For the CLI, the relevant bits of code
Keith> could be put into a separate function trivially enough. I didn't do
Keith> that this round because I was not planning to add this feature to
Keith> anything more than break_command. [list_command would be a follow-on
Keith> feature addition.] But I'll do that before submitting again.

FWIW I'd rather get the first bits in than delay the patch for a new
feature.  It's easy enough to do follow-ups, and they're easier to
review besides.

Tom