Allow source debugger reconnection (#1667)

Allow to wait for a new debugger connection once the previous one
is disconnected:
- when receiving a detach command
- when the client socket is closed (for example, lldb process is killed)

core/iwasm/libraries/debug-engine/gdbserver.h

@@ -56,6 +56,12 @@ wasm_create_gdbserver(const char *host, int32 *port);
 bool
 wasm_gdbserver_listen(WASMGDBServer *server);
 
+bool
+wasm_gdbserver_accept(WASMGDBServer *server);
+
+void
+wasm_gdbserver_detach(WASMGDBServer *server);
+
 void
 wasm_close_gdbserver(WASMGDBServer *server);