Fix some crashes in dartk.

tests/co19/co19-kernel.status

 # Copyright (c) 2016, 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.
 
 # Disable tests globally for kernel.
 [ $compiler == dartk || $compiler == dartkp ]
 Language/Libraries_and_Scripts/Imports/static_type_t01: Skip # No support for deferred libraries.
 LibTest/async/DeferredLibrary/DeferredLibrary_A01_t01: Skip # No support for deferred libraries.
 LibTest/isolate/*: Skip # No support for isolates ATM.
 
@@ skipping 18 matching lines @@
 # Override tests marked as failing elsewhere.
 [ $compiler == dartk || $compiler == dartkp ]
 Language/Libraries_and_Scripts/Exports/reexport_t01: Pass
 Language/Functions/Formal_Parameters/Optional_Formals/syntax_t14: Pass
 
 ###############################################################################
 # Dartk Entries
 ###############################################################################
 
 [ $compiler == dartk || $compiler == dartkp ]
-Language/Classes/Constructors/Generative_Constructors/formal_parameter_t01: DartkCrash
-Language/Classes/Constructors/Generative_Constructors/formal_parameter_t03: DartkCrash
-Language/Classes/Constructors/Generative_Constructors/formal_parameter_t04: DartkCrash
-Language/Classes/Constructors/Generative_Constructors/formal_parameter_t05: DartkCrash
-Language/Classes/Constructors/Generative_Constructors/formal_parameter_t06: DartkCrash
-Language/Classes/Constructors/Generative_Constructors/initializing_this_t02: DartkCrash
 Language/Classes/Getters/static_getter_t02: DartkCompileTimeError
 Language/Enums/syntax_t08: MissingCompileTimeError
 Language/Enums/syntax_t09: MissingCompileTimeError
 Language/Expressions/Function_Invocation/Unqualified_Invocation/instance_context_invocation_t03: MissingCompileTimeError
 Language/Expressions/Function_Invocation/Unqualified_Invocation/instance_context_invocation_t04: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t17: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t18: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t21: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t22: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t23: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t24: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t25: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t26: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t27: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t28: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t29: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t30: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t31: MissingCompileTimeError
 Language/Expressions/Identifier_Reference/built_in_not_dynamic_t32: MissingCompileTimeError
 Language/Interfaces/Superinterfaces/Inheritance_and_Overriding/same_name_method_and_getter_t01: DartkCompileTimeError
 Language/Interfaces/Superinterfaces/Inheritance_and_Overriding/same_name_method_and_getter_t02: DartkCompileTimeError
 Language/Libraries_and_Scripts/Exports/syntax_t01: MissingCompileTimeError
 Language/Libraries_and_Scripts/Exports/syntax_t04: MissingCompileTimeError
 Language/Libraries_and_Scripts/Exports/syntax_t05: MissingCompileTimeError
 Language/Libraries_and_Scripts/Exports/syntax_t06: MissingCompileTimeError
 Language/Libraries_and_Scripts/Imports/invalid_uri_deferred_t02: DartkCompileTimeError
-Language/Libraries_and_Scripts/Scripts/top_level_main_t01: DartkCrash
-Language/Libraries_and_Scripts/Scripts/top_level_main_t02: DartkCrash
 Language/Libraries_and_Scripts/definition_syntax_t01: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t03: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t04: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t06: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t07: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t08: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t09: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t10: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t15: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t17: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t18: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t19: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t20: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t21: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t22: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t23: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t24: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t25: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t26: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t27: MissingCompileTimeError
 Language/Libraries_and_Scripts/definition_syntax_t29: MissingCompileTimeError
+Language/Libraries_and_Scripts/Scripts/top_level_main_t05: RuntimeError # 'main' getter not supported
 Language/Libraries_and_Scripts/top_level_syntax_t02: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t03: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t04: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t05: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t06: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t07: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t08: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t09: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t10: MissingCompileTimeError
 Language/Libraries_and_Scripts/top_level_syntax_t11: MissingCompileTimeError
@@ skipping 87 matching lines @@
 Language/Libraries_and_Scripts/Imports/static_type_t01/01: Pass
 Language/Libraries_and_Scripts/Imports/static_type_t01/02: Pass
 Language/Libraries_and_Scripts/Imports/static_type_t01/03: Pass
 Language/Libraries_and_Scripts/Imports/static_type_t01/04: Pass
 Language/Libraries_and_Scripts/Imports/static_type_t01/05: Pass
 Language/Libraries_and_Scripts/Imports/static_type_t01/06: Pass
 Language/Libraries_and_Scripts/Imports/static_type_t01/07: Pass
 
 # dartk: JIT failures (debug)
 [ $compiler == dartk && $runtime == vm && $mode == debug ]
-Language/Libraries_and_Scripts/Scripts/top_level_main_t05: Crash  # !main_obj.IsNull()
 
 # dartk: precompilation failures
 [ $compiler == dartkp && $runtime == dart_precompiled ]
 Language/Expressions/Constants/exception_t01: Crash
 Language/Expressions/Constants/exception_t02: Crash
 
 # dartk: precompilation failures (debug)
 [ $compiler == dartkp && $runtime == dart_precompiled && $mode == debug ]
-Language/Libraries_and_Scripts/Scripts/top_level_main_t05: Crash  # !main_obj.IsNull()