Invert this instruction.
If the instruction is composite (i.e. has a definition), then its definition will be recursively inverted.
Special instructions inheriting from Instruction can implement their own inverse (e.g. T and Tdg, Barrier, etc.)
a fresh instruction for the inverse
- রিটার্ন টাইপ
CircuitError -- if the instruction is not composite and an inverse has not been implemented for it.