Issue 3531. Don't allow using built-in identifier as import prefix

compiler/java/com/google/dart/compiler/parser/ParserErrorCode.java

 // 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.
 
 package com.google.dart.compiler.parser;
 
 import com.google.dart.compiler.ErrorCode;
 import com.google.dart.compiler.ErrorSeverity;
 import com.google.dart.compiler.SubSystem;
 
 /**
  * {@link ErrorCode}s for parser.
  * <p>
  * The convention in this file (with some exceptions) is that the enumeration name matches at least
  * the beginning default English translation of the message.
  */
 public enum ParserErrorCode implements ErrorCode {
   ABSTRACT_MEMBER_IN_INTERFACE("Abstract members are not allowed in interfaces"),
   ABSTRACT_METHOD_WITH_BODY("Abstract method cannot have a body"),
   ABSTRACT_TOP_LEVEL_ELEMENT("Only class can be abstract top-level element"),
   BREAK_OUTSIDE_OF_LOOP("'break' used outside of loop, case statement"),
+  RESERVED_WORD_AS_TYPE_NAME("Reserved word cannot be used as type name"),
   BUILT_IN_IDENTIFIER_AS_TYPE_NAME("Built-in identifier cannot be used as type name"),
   BUILT_IN_IDENTIFIER_AS_TYPEDEF_NAME("Built-in identifier can not be used as type alias name"),
   BUILT_IN_IDENTIFIER_AS_TYPE_VARIABLE_NAME("Built-in identifier can not be used as type variable name"),
   CATCH_OR_FINALLY_EXPECTED("catch or finally clause expected."),
   CONTINUE_OUTSIDE_OF_LOOP("'continue' used outside of loop or case statement"),
   DEFAULT_VALUE_CAN_NOT_BE_SPECIFIED_IN_CLOSURE(
       "Default values cannot be specified in closure parameter"),
   DEFAULT_VALUE_CAN_NOT_BE_SPECIFIED_IN_TYPEDEF(
       "Default values cannot be specified in closure type definition"),
   DEFAULT_POSITIONAL_PARAMETER("Positional parameters cannot have default values"),
@@ skipping 99 matching lines @@
   @Override
   public SubSystem getSubSystem() {
     return SubSystem.PARSER;
   }
 
   @Override
   public boolean needsRecompilation() {
     return true;
   }
 }