Remove dart2dart support from testing scripts and status files

tests/standalone/standalone.status

 # Copyright (c) 2013, 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.
 
 # WARNING:
 # Tests using the multitest feature where failure is expected should *also* be
 # listed in tests/lib/analyzer/analyze_tests.status without the "standalone"
 # prefix.
 
 package/invalid_uri_test: Fail, OK # CompileTimeErrors intentionally
@@ skipping 89 matching lines @@
 io/arguments_test: CompileTimeError, OK # Cannot pass arguments to d8.
 
 [ $compiler == dart2js && $runtime == none ]
 io/arguments_test: Fail # DartOptions not supported by dart2js, and issue 14200.
 medium_integer_test: Pass # The test only fails at runtime, not at compilation.
 oom_error_stacktrace_test: Pass # The test only fails at runtime.
 
 [ $compiler == dart2js && $browser ]
 *: Skip
 
-[ $compiler == dart2dart ]
-# Skip until we stabilize language tests.
-*: Skip
-
 [ $arch == simarm || $arch == simarmv5te || $arch == simmips]
 out_of_memory_test: Skip # passes on Mac, crashes on Linux
 oom_error_stacktrace_test: Skip # Fails on Linux
 
 [ $arch == simmips || $arch == mips ]
 javascript_int_overflow_test: Skip # --throw_on_javascript_int_overflow not supported on MIPS.
 
 [ $arch == mips ]
 io/signals_test: Fail # Issue 17440
 io/file_stat_test: Fail # Issue 17440
@@ skipping 252 matching lines @@
 io/windows_file_system_links_test: Crash # Instance of 'TypeOperator': unimplemented in CodeGenerator
 io/zlib_test: Crash # (throw _buildException('asyncEnd() was called before asyncStart().')): Unhandled node
 medium_integer_test: Crash # Instance of 'TypeOperator': unimplemented in CodeGenerator
 oom_error_stacktrace_test: Crash # Instance of 'TypeOperator': unimplemented in CodeGenerator
 out_of_memory_test: Crash #  "on T" catch block
 priority_queue_stress_test: Crash # cannot compile methods that need interceptor calling convention.
 slowpath_safepoints_test: Crash # handleStaticFunctionGet: function(noop)
 status_expression_test: Crash # (throw new ExpectException(message)): Unhandled node
 typed_array_test: Crash # Instance of 'TypeOperator': unimplemented in CodeGenerator
 verified_mem_test: Crash # unsupported element kind: a:field