Partial loops over components cause panic in witness extension

[fabian1409]

Looping over components and skipping e.g., the 0th element, causes a panic during the witness extension. Probably a bug in our compiler (there were similar issues in the past).

A minimal example that runs with snarkjs and fails with co-circom:

pragma circom 2.0.0;
include "comparators.circom";

template Main(inputs) {
    component isZero[inputs+1];
    for (var i = 1; i < inputs+1; i++) {
            isZero[i] = IsZero();
            isZero[i].in <== 1;
    }
}

component main = Main(2);

Panic:

thread panicked at ./collaborative-circom-main/co-circom/circom-mpc-vm/src/mpc_vm.rs:463:32:
range end index 9 out of range for slice of length 7

This is probably the reason why the witness extension for HinkalswapperM1x2x1 is wrong.