First stab at mixins in VM compiler

tests/language/language.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.
 
 # This directory contains tests that are intended to show the
 # current state of the language.
 
 # In order to maintain maximum test coverage for all builds,
 # please use the following procedure to mark a test
 # failed on architectures other than the one you are working on.
@@ skipping 38 matching lines @@
 compile_time_constant10_test/none: Fail # issue 5214
 
 export_cyclic_test: Fail, Crash # issue 6060
 duplicate_export_negative_test: Fail # issue 6134
 type_annotation_test/04: Fail # Issue 6970
 type_annotation_test/06: Fail # Issue 6973
 type_annotation_test/09: Fail # Issue 6973
 
 type_parameter_literal_test: Fail # Issue 7551
 
-mixin_field_test: Fail
-mixin_is_test: Fail
-mixin_method_test: Fail
-mixin_naming_test: Fail
-mixin_extends_field_test: Fail
-mixin_extends_is_test: Fail
-mixin_extends_method_test: Fail
-mixin_mixin_test: Fail
 mixin_illegal_syntax_test/none: Fail
-mixin_illegal_superclass_test/none: Fail
-mixin_illegal_constructor_test/none: Fail
-mixin_illegal_static_access_test: Fail
-mixin_illegal_super_use_test/none: Fail
-mixin_implements_test: Fail
 mixin_type_parameters_mixin_test: Fail
 mixin_type_parameters_super_test: Fail
 mixin_type_parameters_mixin_extends_test: Fail
 mixin_type_parameters_super_extends_test: Fail
-mixin_this_use_test: Fail
 
 [ $compiler == none && ($system == macos || $system == linux) && $arch == ia32 && $checked ]
 gc_test: Skip  # Issue 1487, flaky.
 
 [ $compiler == none && $mode == debug ]
 gc_test: Skip  # Takes too long.
 
 [ $compiler == none && $unchecked ]
 
 # Only checked mode reports an error on type assignment
@@ skipping 494 matching lines @@
 *: Skip
 
 [ $arch == simarm ]
 *: Skip
 
 [ $arch == mips ]
 *: Skip
 
 [ $arch == simmips ]
 *: Skip