What's the problem this feature will solve?

The current encoding for the CNOT-constraints in the Clifford synthesizer assumes all-to-all connectivity. Many quantum computing platforms only offer limited qubit connectivity.

Describe the solution you'd like

Allow passing a coupling map to the synthesizer. A class for this already exists within QMAP. The only thing that changes is the encoding loop for the two-qubit constraints.

It would be of general interest to see how a constant limited connectivity might help scalability to larger circuits as the CNOT constraints are the (asymptotically) dominant factor for the size of the encoding.