Volatile doesn't build on the latest nightly

[KernelFreeze]

error[E0599]: no method named `assert_len` found for type parameter `impl RangeBounds<usize>` in the current scope
   --> /home/kernel/.cargo/registry/src/github.com-1ecc6299db9ec823/volatile-0.4.3/src/lib.rs:627:17
    |
627 |         } = src.assert_len(self.reference.len());
    |                 ^^^^^^^^^^ method not found in `impl RangeBounds<usize>`

error: aborting due to previous error

$ rustc --version
rustc 1.52.0-nightly (476acbf1e 2021-03-03)