`tooling/provekit-fixtures/tests/shared/mod`: support fields whose base and extension differ by drawing the LogUp

[recmo]

On 2026-07-13 in 61744fa “Merge pull request #470 from worldfnd/feat/base-field-witness-commit”:

support fields whose base and extension differ by drawing the LogUp
challenges in the base field.

}

/// Challenge-bearing roundtrip suite (LogUp + multi-challenge). The witness
/// holds challenge-derived (ext) values, so this requires an `Identity` field
/// where the base and extension fields coincide.
// TODO: support fields whose base and extension differ by drawing the LogUp
// challenges in the base field.
#[macro_export]
macro_rules! challenge_roundtrip_suite {
    ($field:ty, $register:path) => {
        #[test]
        fn logup_lookup_size_sweep_roundtrip() {

From tooling/provekit-fixtures/tests/shared/mod.rs:413