Don’t ignore -Wclobbered in emacs-module.c

Don’t ignore -Wclobbered in emacs-module.c

This fix is also prompted by Emacs bug#71744.
* src/emacs-module.c: Do not ignore -Wclobbered.
(MODULE_HANDLE_NONLOCAL_EXIT): Fix violations of the C standard,
where setjmp clobbered env and internal_cleanup.
(module_extract_big_integer) [GCC_LINT && __GNUC__ && !__clang__]:
Work around GCC -Wclobbered false positive for ‘sign’.

(cherry picked from commit cfa5a634e91f5c232a71ec212679165074dc480b)