Fixes to enable compiling with new rust.

Compiling wiht newest nightly failed this way:

    error: attributes starting with `rustc` are reserved for use by the `rustc` compiler
      --> /home/jhenner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rustix-0.37.26/src/backend/linux_raw/io/errno.rs:28:25
       |
    28 | #[cfg_attr(rustc_attrs, rustc_layout_scalar_valid_range_start(0xf001))]

Author: jarovo