Fix incorrect desugaring of cascades.

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.
 #
 # 1) Copy the old version of the test to
 #    tests/language/src/test_name_[dartc|vm]_test.dart.
 #    to maintain coverage.
 # 2) File a bug on each architecture for the failure due to the language change.
 # 3) Update the language/src directory with the updated test.
 
 [ $compiler == none ]
 built_in_identifier_prefix_test: Fail # http://dartbug.com/6970
 library_juxtaposition_test: Fail # Issue 6877
 gc_test: Pass, Fail # Issue 1487
 pseudo_kw_illegal_test/14: Fail  # Issue 356
 method_override2_test/00: Fail # Issue 7076.
 method_override2_test/02: Fail # Issue 7076.
 method_override2_test/03: Fail # Issue 7076.
-cascade_2_test: Fail # Issue 7665.
 
 # These bugs refer currently ongoing language discussions.
 constructor5_test: Fail           # (Discussion ongoing)
 
 constructor6_test: Fail           # Issue 6422
 closure_in_initializer_test: Fail # Issue 6422
 
 # Regular bugs which should be fixed.
 const_init6_negative_test: Fail       # Issue 811
 super_first_constructor_test: Fail # Issue 1372.
@@ skipping 494 matching lines @@
 
 [ $compiler == dart2dart && $minified ]
 # TODO(tball): Assign proper bug numbers.
 class_literal_test/none: Fail
 
 import_core_prefix_test: Pass
 prefix22_test: Pass
 invocation_mirror_test: Fail, OK # hardcoded names.
 invocation_mirror2_test: Fail, OK # hardcoded names.
 super_call4_test: Fail, OK # hardcoded names.