The new compiler, sometimes called "stage2" or "stage3" is in many ways better than the old compiler. All 0.10.x releases will have the -fstage1 option; the upgrade only will become mandatory starting with 0.11.0.0. For Zig, building itself went from using 9. is a comptime-only function due to its Comptime only return type. However, pointers are still zero bit types.
