e16dbb7888
The parser now warns about use of mutbl-ref mode, though it's kind of a lie since this commit doesn't remove support for the mode. Changed move_val_init to have stage0 and stage1/2 versions, the latter of which is demoded. Changed the type that the typechecker expects the move_val_init intrinsic to have. After this is pushed, I can make a new snapshot, which will remove the need for the stage0 versions.