bug#64272: 28.1; lisp_file_lexically_bound_p behavior mismatches file local variables

[LdBeth]

>>>>> In <jwvleg7m9ot.fsf-monnier+emacs@gnu.org> 
>>>>>   Stefan Monnier <monnier@iro.umontreal.ca> wrote:
> So maybe we should export `lisp_file_lexically_bound_p` to
> ELisp, let the byte-compiler (and maybe also
> `emacs-lisp-mode`) verify that it gives the same answer as
> `hack-local-variables-prop-line`, and emit a loud warning if
> it doesn't.

I think it is a good idea to have byte-compiler check that.

The context of how this bug reveal is a newbie user
asked why the lexical-binding does not apply in the .emacs
file and turns out there is a leading space in the first
line of the .emacs (well to be honest only scheme people
does wired things with letrec in their .emacs file)

In the context of sharing .emacs files, the files are not likely to be
compiled, so it is better also to check that in emacs-lisp-mode, like,
when the file is opened.

---
ldb