Make it possible to overwrite options to ar using AR_OPTIONS
Make it possible to overwrite options to ar using AR_OPTIONS

No convention for naming of this variable afaict

Mostly useful as an escape hatch when we for whatever reason do the
wrong thing, as in #1702 when used with emconfigure

webmaster128/botan,webmaster128/botan,webmaster128/botan,webmaster128/botan,randombit/botan,webmaster128/botan,randombit/botan,randombit/botan,randombit/botan,randombit/botan