Fix strong mode errors in dart:io.

runtime/bin/socket_patch.dart

Index: runtime/bin/socket_patch.dart
diff --git a/runtime/bin/socket_patch.dart b/runtime/bin/socket_patch.dart
index 8025ab40b47d481f1f40e929e7a572b78e3254b4..2d3ba73b3f7d2abe4aee960eae131c8b7fdc8ce1 100644
--- a/runtime/bin/socket_patch.dart
+++ b/runtime/bin/socket_patch.dart
@@ -46,6 +46,11 @@ patch class InternetAddress {
       String host, {InternetAddressType type: InternetAddressType.ANY}) {
     return _NativeSocket.lookup(host, type: type);
   }
+
+  /* patch */ static InternetAddress _cloneWithNewHost(
+      InternetAddress address, String host) {
+    return (address as _InternetAddress)._cloneWithNewHost(host);
+  }
 }
 
 patch class NetworkInterface {
@@ -1250,7 +1255,7 @@ class _RawSocket extends Stream<RawSocketEvent>
     if (fd != null) _getStdioHandle(native, fd);
     var result = new _RawSocket(native);
     if (fd != null) {
-      var socketType = _StdIOUtils._socketType(result._socket);
+      var socketType = _StdIOUtils._nativeSocketType(result._socket);
       result._isMacOSTerminalInput =
           Platform.isMacOS && socketType == _STDIO_HANDLE_TYPE_TERMINAL;
     }