dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'

dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'

Accept these additional query forms:

   echo "file $filestr +_" > control

       path/to/file.c:100	# as from control, column 1
       path/to/file.c:1-100	# or any legal line-range
       path/to/file.c:func_A	# as from an editor/browser
       path/to/file.c:drm_*	# wildcards still work
       path/to/file.c:*_foo	# lead wildcard too

1st 2 examples are treated as line-ranges, 3-5 are treated as func's

Doc these changes, and sprinkle in a few extra wild-card examples and
trailing # explanation texts.

Acked-by: <jbaron@akamai.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200719231058.1586423-14-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>