Remove support for String operator + from dart2js.

dart/tests/co19/co19-leg.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.
 
 [ $compiler == dart2js && $system == macos && $runtime == d8 ]
 LibTest/core/Math/acos_A01_t01: Fail, OK
 LibTest/core/Math/asin_A01_t01: Fail, OK
 LibTest/core/Math/atan_A01_t01: Fail, OK
 
 
@@ skipping 153 matching lines @@
 
 
 #
 # Issues with co19 test suite.
 #
 # If you add anything here, either file a bug against the Dart
 # langauge specification, co19 test suite, or add a comment that ahe@
 # can understand so he can file a bug later.
 #
 [ $compiler == dart2js ]
+Language/10_Expressions/06_Lists_A08_t01: Fail, OK # co19 issue 145.
 Language/10_Expressions/07_Maps_A01_t01: Fail, OK # Bad test: an expression statement cannot start with a map literal (specification bug).
 Language/10_Expressions/08_Function_Expressions_A01_t05: Fail, OK # Function declaration takes precedence over function expression.
+Language/10_Expressions/13_Function_Invocation/1_Actual_Argument_List_Evaluation_A01_t01: Fail, OK # co19 issue 145.
 Language/10_Expressions/19_Bitwise_Expressions_A01_t01: Fail, OK # Function declaration takes precedence over function expression.
 Language/10_Expressions/20_Equality_A01_t01: Fail, OK # Function declaration takes precedence over function expression.
 Language/10_Expressions/21_Relational_Expressions_A01_t01: Fail, OK # Function declaration takes precedence over function expression.
 Language/10_Expressions/22_Shift_A01_t01: Fail, OK # Function declaration takes precedence over function expression.
 Language/10_Expressions/26_Postfix_Expressions_A01_t01: Fail, OK # A map literal cannot start an expression statement.
 Language/10_Expressions/27_Assignable_Expressions_A01_t27: Fail, OK # A map literal cannot start an expression statement.
 Language/11_Statements/02_Expression_Statements_A01_t05: Fail, OK # Bad test: an expression statement cannot start with a map literal (specification bug).
 Language/11_Statements/02_Expression_Statements_A01_t07: Fail, OK # Bad test: an expression statement cannot start with a map literal (specification bug).
+Language/11_Statements/07_Do_A02_t02: Fail, OK # co19 issue 145.
 Language/12_Libraries_and_Scripts/12_Libraries_and_Scripts_A02_t01: Fail, OK # Dart issue 2259.
 Language/12_Libraries_and_Scripts/12_Libraries_and_Scripts_A02_t03: Fail, OK # Dart issue 2259.
 Language/12_Libraries_and_Scripts/12_Libraries_and_Scripts_A04_t20: Fail, OK # Dart issue 2259.
 LibTest/core/String/String_class_A02_t01: Fail, OK # compiler cancelled: Unhandled non-BMP character: U+10000
 LibTest/core/String/charCodeAt_A01_t01: Fail, OK # compiler cancelled: Unhandled non-BMP character: U+10000
 LibTest/core/String/charCodes_A01_t01: Fail, OK # compiler cancelled: Unhandled non-BMP character: U+10000
 
 [ $compiler == dart2js && $runtime == d8 ]
 LibTest/core/RegExp/Pattern_semantics/firstMatch_CharacterClassEscape_A04_t01: Fail, Pass # issue 3333
 LibTest/core/RegExp/Pattern_semantics/firstMatch_CharacterClassEscape_A03_t01: Fail, Pass # issue 3333
@@ skipping 496 matching lines @@
 Language/12_Libraries_and_Scripts/2_Imports_A07_t01: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/2_Imports_A07_t02: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/2_Imports_A08_t02: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/3_Includes_A01_t01: Fail, OK # @compile-error
 Language/12_Libraries_and_Scripts/3_Includes_A03_t03: Fail, OK # @compile-error
 Language/13_Types/3_Type_Declarations/1_Typedef_A07_t02: Fail, OK # @compile-error
 Language/13_Types/3_Type_Declarations/1_Typedef_A07_t03: Fail, OK # @compile-error
 Language/13_Types/7_Type_Void_A01_t02: Fail, OK # @compile-error
 Language/14_Reference/1_Lexical_Rules/1_Reserved_Words_A30_t04: Fail, OK # @compile-error
 Language/14_Reference/1_Lexical_Rules_A02_t06: Fail, OK # @compile-error