Support BottomType in the VM Kernel reader

runtime/vm/kernel_to_il.cc

 // 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.
 
 #include <set>
 
 #include "vm/kernel_to_il.h"
 
 #include "vm/compiler.h"
 #include "vm/intermediate_language.h"
@@ skipping 4825 matching lines @@
 void DartTypeTranslator::VisitDynamicType(DynamicType* node) {
   result_ = Object::dynamic_type().raw();
 }
 
 
 void DartTypeTranslator::VisitVoidType(VoidType* node) {
   result_ = Object::void_type().raw();
 }
 
 
+void DartTypeTranslator::VisitBottomType(BottomType* node) {
+  result_ =
+      dart::Class::Handle(Z, I->object_store()->null_class()).CanonicalType();

[Kevin Millikin (Google), 2017/05/03 21:01:06]

This is the only interesting code.  Is this the right type?  Regis, is there a
better way?  There are accessors for dynamic_type and void_type in Object, but
nothing for this type.

[regis, 2017/05/04 09:35:10]

This should be fine.

+}
+
+
 const TypeArguments& DartTypeTranslator::TranslateTypeArguments(
     DartType** dart_types,
     intptr_t length) {
   bool only_dynamic = true;
   for (intptr_t i = 0; i < length; i++) {
     if (!dart_types[i]->IsDynamicType()) {
       only_dynamic = false;
       break;
     }
   }
@@ skipping 2009 matching lines @@
     thread->clear_sticky_error();
     return error.raw();
   }
 }
 
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)