pub fn zeroed_f_vec<F: Field>(len: usize) -> Vec<F> {
    debug_assert!(std::mem::size_of::<F>() == 4);

    let vec = vec![0u32; len];
    unsafe { std::mem::transmute::<Vec<u32>, Vec<F>>(vec) }
}
Returns a vector of zeros of the given length. This is faster than vec![F::zero(); len] which
requires copying.

This function is safe to use only for fields that can be transmuted from 0u32.
crates/core/machine/src/utils/mod.rs