https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63651
--- Comment #16 from mrs at gcc dot gnu.org <mrs at gcc dot gnu.org> --- We can fixincludes NS_BLOCKS_AVAILABLE support back in, this would disappear interfaces that cannot be supported. In the past, this was a safe thing to do, and might well be still safe wrt the runtime. Deeper language issues would likely need someone to do real work. No really nice fix for that other than someone who wanted to do the work stepping forward. Until then, SDK support for older OSes might be the old way to get code compiled on newer systems. We should be able to steal code from MIT style runtimes to put into newer systems, if we can get FSF approval for incorporating code they don't own. This should be easy enough, we don't vend sell or ship a competing abi compatible runtime, so, bundling one I think should be trivial, if we want to.
