Build fails on armv7 musl

[JustSoup312]

Build fails on Alpine Linux on armv7 with:

error: literal out of range for `usize`
    --> src/cmp.rs:1088:30
     |
1088 |                 skip_b: Some(1_152_921_504_606_846_976 * 2),
     |                              ^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = note: the literal `1_152_921_504_606_846_976` does not fit into the type `usize` whose range is `0..=4294967295`
     = note: `#[deny(overflowing_literals)]` on by default

I believe this is because of 32 vs 64 bit implementations of usize differing in maximum values, but I could be wrong.