Allow javascript.options.ion, javascript.options.baselinejit, and javascript.options.native_regexp at the highest security level

At the highest security level JavaScript for webpages is disabled, so these features cannot be used for fingerprintina and expluatation. But a large part of the browser is written in JS itself and disabling this features slows the web browser down. I suggest to enable them for the highest security mode as a temporary solution and use 2 different settings or store there numbers as bit flags to control these features for frowser GUI and webpages separately, if it is possible.