Add a configure option for NATIVE_FULL_AOT?

[Ulrich Mueller]

lisp/Makefile.in has a conditional for NATIVE_FULL_AOT which enables
native compilation of all elisp files. Presumably distros would want to
define this when packaging Emacs.

AFAICS this variable is not documented. I wonder if it could be made a
configure option, so a) it would be discoverable and b) its value would
be recorded in system-configuration-options.

Not sure if --with-native-full-aot would be the best possible name.