Better error-message when bind fails.

runtime/bin/socket_fuchsia.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #if !defined(DART_IO_DISABLED)
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_FUCHSIA)
 
 #include "bin/socket.h"
@@ skipping 27 matching lines @@
 }
 
 
 intptr_t Socket::CreateBindConnect(const RawAddr& addr,
                                    const RawAddr& source_addr) {
   UNIMPLEMENTED();
   return -1;
 }
 
 
+bool Socket::IsBindError(intptr_t error_number) {
+  UNIMPLEMENTED();
+  return false;
+}
+
+
 intptr_t Socket::Available(intptr_t fd) {
   UNIMPLEMENTED();
   return -1;
 }
 
 
 intptr_t Socket::Read(intptr_t fd, void* buffer, intptr_t num_bytes) {
   UNIMPLEMENTED();
   return -1;
 }
@@ skipping 175 matching lines @@
   UNIMPLEMENTED();
   return false;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_FUCHSIA)
 
 #endif  // !defined(DART_IO_DISABLED)