dcl-back-to-indentation is an interactive compiled Lisp function in `
Move point to the first non-whitespace character on this line.
Leading $ and labels counts as whitespace in this case.
If this is a comment line then move to the first non-whitespace character
in the comment.
Typing M-x dcl-back-to-indentation several times in a row will move point to other
`interesting' points closer to the left margin, and then back to the
rightmost point again.
E.g. on the following line, point would go to the positions indicated
by the numbers in order 1-2-3-1-... :
$ label: command
3 2 1