C-M-j or M-j? What's going on with these bindings?

[Alan Mackenzie]

M-j and C-M-j are both bound to `indent-new-comment-line'.  These
bindings are adjacent to eachother in .../lisp/bindings.el.

This seems a bit like a waste of a good binding.

The documentation (in programs.texi) mentions only C-M-j, not M-j.

Intuitively, M-j seems to me to be the better binding - as well as being
easier to type, it's kind of the arithmetic mean of C-j and M-;.

I think programs.texi should mention both bindings.

What's up with these bindings and their documentation?

-- 
Alan Mackenzie (Munich, Germany)