Disable hoisting CheckClass due to excessive deoptimization.

runtime/vm/object.cc

 // 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.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 4989 matching lines @@
     set_is_inlinable(false);
   }
 }
 
 
 void Function::SetIsNativeAutoSetupScope(bool value) const {
   ASSERT(is_native());
   set_is_optimizable(value);
 }
 
+
 void Function::set_is_optimizable(bool value) const {
   set_kind_tag(OptimizableBit::update(value, raw_ptr()->kind_tag_));
 }
 
 
+void Function::set_allows_hoisting_check_class(bool value) const {
+  set_kind_tag(
+      AllowsHoistingCheckClassBit::update(value, raw_ptr()->kind_tag_));
+}
+
+
 void Function::set_is_native(bool value) const {
   set_kind_tag(NativeBit::update(value, raw_ptr()->kind_tag_));
 }
 
 
 void Function::set_is_abstract(bool value) const {
   set_kind_tag(AbstractBit::update(value, raw_ptr()->kind_tag_));
 }
 
 
@@ skipping 493 matching lines @@
   result.set_token_pos(token_pos);
   result.set_end_token_pos(token_pos);
   result.set_num_fixed_parameters(0);
   result.set_num_optional_parameters(0);
   result.set_usage_counter(0);
   result.set_deoptimization_counter(0);
   result.set_optimized_instruction_count(0);
   result.set_optimized_call_site_count(0);
   result.set_is_optimizable(is_native ? false : true);
   result.set_is_inlinable(true);
+  result.set_allows_hoisting_check_class(true);
   if (kind == RawFunction::kClosureFunction) {
     const ClosureData& data = ClosureData::Handle(ClosureData::New());
     result.set_data(data);
   }
   return result.raw();
 }
 
 
 RawFunction* Function::Clone(const Class& new_owner) const {
   ASSERT(!IsConstructor());
@@ skipping 11778 matching lines @@
   return "_MirrorReference";
 }
 
 
 void MirrorReference::PrintToJSONStream(JSONStream* stream, bool ref) const {
   Instance::PrintToJSONStream(stream, ref);
 }
 
 
 }  // namespace dart