test failure on 32-bit.

[plugwash]

After updating the h3 crate in Debian I discovered that tests fail on 32-bit systems.

---- qpack::prefix_int::test::codec_5_bits stdout ----
thread 'qpack::prefix_int::test::codec_5_bits' panicked at src/qpack/prefix_int.rs:101:67:
called `Result::unwrap()` on an `Err` value: Overflow

---- qpack::prefix_int::test::codec_8_bits stdout ----
thread 'qpack::prefix_int::test::codec_8_bits' panicked at src/qpack/prefix_int.rs:101:67:
called `Result::unwrap()` on an `Err` value: Overflow

Digging into the git history I found that the encode and decode functions previously used usize and were changed to use u64 instead of usize ( #223 ) however the value of MAX_POWER was not changed and as a result decoding large numbers still fails.

I believe the correct fix is to use the same MAX_POWER value on all targets and intend to implement that in Debian, but feedback would be appreciated.

[seanmonstar]

Your fix sounds right to me. Want to submit a PR?

[plugwash]

Patch is at https://salsa.debian.org/rust-team/debcargo-conf/-/blob/master/src/h3/debian/patches/allow-decoding-large-numbers-on-32-bit.patch