Evm can run with SpecId::Cancun hardfork without KZG point evaluation precompile

[Wodann]

The addition of the KZG point evaluation precompile to the list of precompiles is hidden behind the c-kzg feature flag:

    /// Returns precompiles for Cancun spec.
    ///
    /// If the `c-kzg` feature is not enabled KZG Point Evaluation precompile will not be included,
    /// effectively making this the same as Berlin.
    pub fn cancun() -> &'static Self {
        static INSTANCE: OnceBox<Precompiles> = OnceBox::new();
        INSTANCE.get_or_init(|| {
            let precompiles = Self::berlin().clone();

            // Don't include KZG point evaluation precompile in no_std builds.
            #[cfg(feature = "c-kzg")]
            let precompiles = {
                let mut precompiles = precompiles;
                precompiles.extend([
                    // EIP-4844: Shard Blob Transactions
                    kzg_point_evaluation::POINT_EVALUATION,
                ]);
                precompiles
            };

            Box::new(precompiles)
        })
    }

This resulted in silent failures when running EIP-4844 transactions on an Evm with SpecId::CANCUN. Instead, I would have expected it to be forbidden to run revm with SpecId::CANCUN if the c-kzg feature flag was missing.

[rakita]

This would mean no wasm support for revm Cancun, even if not all TX are using this precompile.

I didn't success in compaling c-kzg for no std platforms, and there is no alternative (afaik) in rust that we can switch to (similar what we have done with k256 and secp256k1 libs)

[rakita]

It seems there is an alternative in rust: https://github.com/grandinetech/rust-kzg/tree/main/kzg

worth investigating