VM: Restore old implementation of ClassID.cid* fields

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 <map>
 #include <set>
 #include <string>
 
 #include "vm/kernel_to_il.h"
 
@@ skipping 4478 matching lines @@
   fragment_ = instructions;
 }
 
 
 void FlowGraphBuilder::VisitStaticGet(StaticGet* node) {
   Member* target = node->target();
   if (target->IsField()) {
     Field* kernel_field = Field::Cast(target);
     const dart::Field& field =
         dart::Field::ZoneHandle(Z, H.LookupFieldByKernelField(kernel_field));
-    if (kernel_field->IsConst()) {
+    if (field.is_const()) {
       fragment_ = Constant(constant_evaluator_.EvaluateExpression(node));
     } else {
       const dart::Class& owner = dart::Class::Handle(Z, field.Owner());
       const dart::String& getter_name = H.DartGetterName(kernel_field->name());
       const Function& getter =
           Function::ZoneHandle(Z, owner.LookupStaticFunction(getter_name));
       if (getter.IsNull() || !field.has_initializer()) {
         Fragment instructions = Constant(field);
         fragment_ = instructions + LoadStaticField();
       } else {
@@ skipping 1770 matching lines @@
     thread->clear_sticky_error();
     return error.raw();
   }
 }
 
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)