bug#24359: Patch for byte compilation bugs

[npostavs]

There was some suggestion in #23495 (to which I've merged this bug) that
it may have been on purpose, but no confirmation of that, and it doesn't
really make sense to me, so I think your patch is a good idea.

Philipp Stephani <p.stephani2@gmail.com> writes:
>
> * lisp/emacs-lisp/macroexp.el (macroexp--funcall-if-compiled)
> (macroexp--warn-and-return): Use ‘byte-compile-warn’ instead of
> ‘byte-compile-log-warning’.
>
> * lisp/emacs-lisp/bytecomp.el (byte-compile-form, byte-compile-unfold-bcf)
> (byte-compile-setq, byte-compile-funcall): Use
> ‘byte-compile-report-error’ instead of ‘byte-compile-log-warning’.
[...]
> * lisp/emacs-lisp/cconv.el (cconv-convert, cconv--analyze-use)
> (cconv--analyze-function, cconv-analyze-form): Use
> ‘byte-compile-warn’ instead of ‘byte-compile-log-warning’.
>
> * lisp/emacs-lisp/byte-opt.el (byte-compile-inline-expand): Use
> ‘byte-compile-warn’ instead of ‘byte-compile-log-warning’.
>
> * lisp/subr.el (add-to-list): Use ‘byte-compile-report-error’ instead
> of ‘byte-compile-log-warning’.
> (do-after-load-evaluation): Use ‘byte-compile-warn’ instead of
> ‘byte-compile-log-warning’.

I think you can combine all these into one entry.

>  (defun byte-compile-log-warning (string &optional fill level)
> +  "Log a message STRING in `byte-compile-log-buffer'.
> +Also log the current function and file if not already done.  If
> +FILL is non-nil, set ‘warning-fill-prefix’ to four spaces.  LEVEL

Docstrings should use `', which will be converted to ‘’ upon display.