Circuit diagrams: handle integer comparisons, add SX gate

[minestarks]

• add the SX gate to the supported primitives
• handle comparison operators more gracefully.

from:

operation Main() : Result {
    use q = Qubit();
    use reg = Qubit[4];
 
    ApplyToEach(H, reg);
    let num = MeasureInteger(reg);
 
    if num < 8 {
        X(q);
    } else {
        Z(q);
    }
 
    ResetAll(reg);
    MResetZ(q)
}