Issue 5735. Fix for 'export' without 'import'

tests/co19/co19-compiler.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 == dartc ]
 # We are now actually skipping these because of inter-test dependencies.
 Language/13_Libraries_and_Scripts/2_Imports_A02_t21: Skip # TODO(analyzer-team): Please triage this crash.
 Language/13_Libraries_and_Scripts/3_Includes_A01_t23: Skip # TODO(analyzer-team): Please triage this crash.
 Language/13_Libraries_and_Scripts/2_Imports_A03_t07: Skip # TODO(analyzer-team): Please triage this crash.
 
@@ skipping 170 matching lines @@
 
 # co19 issue 218
 Language/10_Expressions/28_Identifier_Reference_A08_t38: Fail, OK
 
 
 Language/10_Expressions/30_Type_Cast_A01_t04: Fail, OK # the expected error is not specified
 Language/13_Libraries_and_Scripts/13_Libraries_and_Scripts_A05_t03: Fail, OK # contains syntax error
 Language/13_Libraries_and_Scripts/13_Libraries_and_Scripts_A05_t04: Fail, OK # contains syntax error
 Language/13_Libraries_and_Scripts/2_Imports_A01_t18: Fail, OK # contains semantic error
 Language/13_Libraries_and_Scripts/2_Imports_A02_t18: Fail, OK # contains syntax error
-Language/13_Libraries_and_Scripts/2_Imports_A02_t20: Fail, OK # contains syntax error
 Language/13_Libraries_and_Scripts/2_Imports_A02_t21: Fail, OK # contains syntax error
-Language/13_Libraries_and_Scripts/2_Imports_A02_t22: Fail, OK # contains syntax error
 Language/13_Libraries_and_Scripts/2_Imports_A02_t24: Fail, OK # co19 issue 243
 Language/13_Libraries_and_Scripts/2_Imports_A05_t02: Fail, OK # invalid directive syntax
 Language/06_Functions/06_Functions_A01_t06: Fail, OK # expecting error that doesn't exist
 Language/06_Functions/2_Formal_Parameters/2_Optional_Formals_A03_t02: Fail, OK # deprecated parameter syntax
 Language/07_Classes/6_Constructors/2_Factories_A05_t01: Fail, OK # should expect error
 Language/07_Classes/6_Constructors/2_Factories_A05_t03: Fail, OK # should expect error
 Language/10_Expressions/05_Strings_A02_t39: Fail, OK # no longer an error
 Language/10_Expressions/05_Strings_A02_t41: Fail, OK # no longer an error
 Language/10_Expressions/05_Strings_A02_t43: Fail, OK # no longer an error
 Language/10_Expressions/05_Strings_A02_t45: Fail, OK # no longer an error
@@ skipping 135 matching lines @@
 Language/11_Statements/05_For/2_For_in_A01_t02: Fail, OK
 Language/11_Statements/08_Switch_A06_t04: Fail, OK
 Language/03_Overview/2_Privacy_A01_t11: Fail, OK
 Language/03_Overview/1_Scoping_A02_t28: Fail, OK
 Language/03_Overview/2_Privacy_A01_t18: Fail, OK
 Language/03_Overview/2_Privacy_A01_t08: Fail, OK
 
 
 [ $runtime == drt && ($compiler == none || $compiler == frog) ]
 *: Skip