Add test for native extensions that copies the extension to a test directory and runs it.

tests/standalone/standalone.status

 # Copyright (c) 2012, 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.
 
 out_of_memory_test: Skip # Issue 2345
 
 package/invalid_uri_test: Fail, OK # Fails intentionally
 
 [ $runtime == vm && $checked ]
 # These tests have type errors on purpose.
 io/process_invalid_arguments_test: Fail, OK
 io/directory_invalid_arguments_test: Fail, OK
 io/file_invalid_arguments_test: Fail, OK
 io/socket_invalid_arguments_test: Fail, OK
 # These test have type errors on purpose and take very long to run in
 # checked mode with no benefit. Skip.
 io/file_fuzz_test: Skip
 io/directory_fuzz_test: Skip
 
 [ $runtime == vm]
 io/many_echo_server_test: Skip        # Bug 5103754
-# These tests fail, crash, and timeout to test the testing infrastructure.
-io/test_extension_test: Fail  # shared library in wrong place (issue 1817)
 # This test fails intermittently.
 io/http_basic_test: Pass, Fail     # Issue 3599
 
 
 [ $runtime == vm && $system == macos]
 # This test fails with "Too many open files" on the Mac OS buildbot.
 io/socket_many_connections_test: Skip
-io/test_extension_test: Skip  # Extensions not implemented on MacOS
 io/http_server_handler_test: Skip # Issue 2637
 
 [ $runtime == vm && $system == windows]
-io/test_extension_test: Skip  # Extensions not implemented on Windows
 io/http_shutdown_test: Skip  # Currently times out on windows
 io/file_system_links_test: Skip  # No links on Windows.
 io/http_connection_header_test: Pass, Fail  # Issue 2959
 
 [ $compiler == none && $runtime == drt ]
 io/*: Skip # Don't run tests using dart:io in the browser
 crypto/*: Skip # Don't run tests using dart:io in the browser
 package/*: Skip # Do not run those in Dartium.
 
 [ $compiler == dartc]
 *: Skip
 
 [ $compiler == frog ]
 *: Skip
 
 [ $arch == x64 ]
 medium_integer_test: Fail # Issue 1146.
 
 
 [ $arch == arm ]
 *: Skip
 
 
 [ $arch == simarm ]
 *: Skip
 
 [ $compiler == dart2js ]
 medium_integer_test: Fail, OK # cannot resolve type Mint
-io/test_extension_test: Fail, OK # dart-ext:test_extension: Illegal argument(s): dart-ext:test_extension
 io/timer_cancel_test: Fail # Needs Timer to run.
 io/timer_cancel1_test: Fail # Needs Timer to run.
 io/timer_cancel2_test: Fail # Needs Timer to run.
 io/multiple_timer_test: Fail # Needs Timer to run.
 io/timer_test: Fail # Needs Timer to run.
 io/timer_repeat_test: Fail # Needs Timer to run.
 
 [ $compiler == dart2js && $runtime == d8 ]
 assert_test: Fail # Assert not implemented
 byte_array_test: Fail, OK # ByteArray
 deoptimization_test: Fail, OK # Requires bigint.
 out_of_memory_test: Fail, OK # d8 handles much larger arrays than Dart VM.
 io/http_parser_test: Fail, OK # ByteArray
 io/options_test: Fail, OK # Cannot pass options to d8.
 
 [ $compiler == dart2js && $runtime == none ]
 io/options_test: Fail
 
 [$compiler == dart2js && $browser ]
 *: Skip
 
 [$compiler == dart2js && $checked ]
 io/http_read_test: Skip # Timeout TODO(ngeoffray): investigate
 io/list_input_stream_test: Skip # Timeout TODO(ngeoffray): investigate
 io/http_headers_test: Fail # TODO(floitsch): I'm on it.
 io/http_date_test: Fail # TODO(floitsch): I'm on it.