Ops which cannot be unrolled are silently ignored.

[Jack J. Woehr]

Unrolling does not test for failure nor throw an exception when an op from the AST is in proper form but yet cannot be unrolled into a circuit.

E.g.,

// Here's an unknown op 'u(a,b,c)'
u(pi/2,pi/4,pi/15) q[0] ;

[Jack J. Woehr]

Fixed in v0.32