Code generation failure when looping over array in an adjointable operation

[cgranade]

Describe the bug

The following operation fails to compile with C# errors:

operation PrepareCatState(register : Qubit[]) : Unit is Adj + Ctl {
    H(register[0]);
    for (target in register[1...]) {
        CNOT(register[0], target);
    }
}

Modifying the operation to not be adjointable works, as does storing the array slice in a local variable before looping:

operation PrepareCatState(register : Qubit[]) : Unit is Adj {
    H(register[0]);
    let targets = register[1...];
    for (target in targets) {
        CNOT(register[0], target);
    }
}

Using an array function also works around the issue:

open Microsoft.Quantum.Arrays;
operation PrepareCatState(register : Qubit[]) : Unit is Adj {
    H(register[0]);
    for (target in Rest(register)) {
        CNOT(register[0], target);
    }
}

To Reproduce

See reproduction at: https://mybinder.org/v2/gist/cgranade/471654e721ff80ca8de8c80a954f6d20/master

System information

[ScottCarda-MS]

Fixed with PR #330