bug#23469: Feature request: automatically instrument forms when setting Edebug breakpoint

[Paul Pogonyshev]

If you issue M-x edebug-set-breakpoint inside a random function
definition, you will get "Not inside instrumented form" error. So, you
need to C-u C-M-x it first manually. In addition to being annoying, it
can also lead to accidental breakpoint loss, since you can't easily
tell if a form is already instrumented and has breakpoints.

Request: instead of signalling an error, Emacs should just
automatically instrument function if I set a breakpoint in it.