Aer to support print out of native code (QObj) as well

Note: Aer can simulate conditional (bfunc) in the QObj and XACC translate IfStmt to bfunc appropriately.
Signed-off-by: Thien Nguyen <nguyentm@ornl.gov>

quantum/plugins/ibm/aer/accelerator/aer_accelerator.cpp

@@ -832,6 +832,14 @@ IbmqNoiseModel::averageTwoQubitGateFidelity() const {
 
   return result;
 }
+
+std::string
+AerAccelerator::getNativeCode(std::shared_ptr<CompositeInstruction> program,
+                              const HeterogeneousMap &config) {
+  auto qobj_str = xacc_to_qobj->translate(program);
+  nlohmann::json j = nlohmann::json::parse(qobj_str)["qObject"];
+  return j.dump(2);
+}
 } // namespace quantum
 } // namespace xacc
 

quantum/plugins/ibm/aer/accelerator/aer_accelerator.hpp

@@ -60,7 +60,8 @@ public:
   void apply(std::shared_ptr<AcceleratorBuffer> buffer,
              std::shared_ptr<Instruction> inst) override;
   bool isInitialized() const { return initialized; }
-
+  std::string getNativeCode(std::shared_ptr<CompositeInstruction> program,
+                            const HeterogeneousMap &config = {}) override;
 private:
   static double calcExpectationValueZ(
       const std::vector<std::pair<double, double>> &in_stateVec,