Backport the (L)GPL-3 avoidance rework to v2020dev0
Push to the v2020dev0 release the fixes that get us both etnaviv and working GL under Xvfb without linking to the GPL-2/LGPL-3 libelf, so downstreams can use them.
Push to the v2020dev0 release the fixes that get us both etnaviv and working GL under Xvfb without linking to the GPL-2/LGPL-3 libelf, so downstreams can use them.