Print OpenCL platform and devices in summary.

src/backend/opencl/wrappers/OclLib.h

@@ -43,6 +43,7 @@ public:
     static const char *lastError();
     static void close();
 
+    static inline bool isInitialized()   { return m_initialized; }
     static inline const String &loader() { return m_loader; }
 
     static cl_command_queue createCommandQueue(cl_context context, cl_device_id device, cl_int *errcode_ret);