Currently, for almost all methods (except `dealloc` and `shrink(_in_place)`) in `AllocRef`, there is a `_zeroed` variant, which blows up the trait. I propose to remove those variants and add a `zeroed: bool` to the signatures. E.g.: ```rust fn alloc(&self, layout: Layout, zeroed: bool) -> Result<...>; fn realloc(&self, ptr: NonNull<u8>, layout: Layout, new_size: usize, zeroed: bool) -> Result<...>; ```