Revert "Add some support for the code-point code-unit distinction."

tests/corelib/corelib.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.
 
-reg_exp_unicode_2_test: Fail # Bug 6592
-
 [ $compiler == none ]
-unicode_test: Fail        # Bug 6706
+unicode_test: Fail        # Bug 5163868
 *dartc_test: Skip
 compare_to2_test: Fail    # Bug 4018
 null_test: Fail           # Bug 5511
 apply_test: Fail # Bug 5670
 apply2_test: Fail # Bug 5670
 
 [ $runtime == ff || $runtime == ie9 || $runtime == jsshell ]
 unicode_test: Fail
 
-[ $compiler == dart2js && ($runtime == chrome || $runtime == drt || $runtime == d8 || $runtime == safari) ]
-string_trim_unicode_test: Fail  # V8 bug 2408
-
 [ $runtime == opera ]
 core_runtime_types_test: Fail
 date_time7_test: Fail
 unicode_test: Fail
 
 [ $runtime == ie9 && ($system == linux || $system == macos) ]
 *: Skip
 
 [ $runtime == safari && ($system == linux || $system == windows) ]
 *: Skip
 
 [ $arch == simarm ]
 *: Skip
 
 [ $arch == arm ]
 *: Skip
 
 [ $compiler == dart2js ]
 math_parse_double_test: Fail # Expect.equals(expected: <78187493520>, actual: <0>)
 math_test: Fail # issue 3333
-surrogate_pair_toUpper_test: Fail # Issue 6707
 
 # Bad test, assumes RegExp.allMatches returns a Collection.
 reg_exp_all_matches_test: Fail, OK # NoSuchMethodError : method not found: 'forEach'
 
 reg_exp4_test: Fail, OK # Expects exception from const constructor.
 
 null_nosuchmethod_test: Fail # Fails to read noSuchMethod from null.
 
 big_integer_vm_test: Fail, OK # VM specific test.
 compare_to2_test: Fail, OK    # Requires bigint support.
@@ skipping 10 matching lines @@
 reg_exp_all_matches_test: Fail # BUG(3304): Maybe this doesn't time out?
 string_base_vm_test: Fail # BUG(3304): Maybe this doesn't time out?
 
 [ $compiler == dart2dart ]
 apply_test: Fail # inherited from VM
 apply2_test: Fail # inherited from VM
 compare_to2_test: Fail # inherited from VM
 null_test: Fail # inherited from VM
 unicode_test: Fail # inherited from VM