Disable hoisting CheckClass due to excessive deoptimization.

runtime/vm/object.h

 // 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 1704 matching lines @@
   bool is_recognized() const {
     return RecognizedBit::decode(raw_ptr()->kind_tag_);
   }
   void set_is_recognized(bool value) const;
 
   bool is_redirecting() const {
     return RedirectingBit::decode(raw_ptr()->kind_tag_);
   }
   void set_is_redirecting(bool value) const;
 
+  bool allows_hoisting_check_class() const {
+    return AllowsHoistingCheckClassBit::decode(raw_ptr()->kind_tag_);
+  }
+  void set_allows_hoisting_check_class(bool value) const;
+
   bool HasOptimizedCode() const;
 
   // Returns true if the argument counts are valid for calling this function.
   // Otherwise, it returns false and the reason (if error_message is not NULL).
   bool AreValidArgumentCounts(intptr_t num_arguments,
                               intptr_t num_named_arguments,
                               String* error_message) const;
 
   // Returns true if the total argument count and the names of optional
   // arguments are valid for calling this function.
@@ skipping 150 matching lines @@
     kConstBit = 5,
     kAbstractBit = 6,
     kVisibleBit = 7,
     kOptimizableBit = 8,
     kInlinableBit = 9,
     kIntrinsicBit = 10,
     kRecognizedBit = 11,
     kNativeBit = 12,
     kRedirectingBit = 13,
     kExternalBit = 14,
+    kAllowsHoistingCheckClassBit = 15,
   };
   class KindBits :
     public BitField<RawFunction::Kind, kKindTagBit, kKindTagSize> {};  // NOLINT
   class StaticBit : public BitField<bool, kStaticBit, 1> {};
   class ConstBit : public BitField<bool, kConstBit, 1> {};
   class AbstractBit : public BitField<bool, kAbstractBit, 1> {};
   class VisibleBit : public BitField<bool, kVisibleBit, 1> {};
   class OptimizableBit : public BitField<bool, kOptimizableBit, 1> {};
   class InlinableBit : public BitField<bool, kInlinableBit, 1> {};
   class IntrinsicBit : public BitField<bool, kIntrinsicBit, 1> {};
   class RecognizedBit : public BitField<bool, kRecognizedBit, 1> {};
   class NativeBit : public BitField<bool, kNativeBit, 1> {};
   class ExternalBit : public BitField<bool, kExternalBit, 1> {};
   class RedirectingBit : public BitField<bool, kRedirectingBit, 1> {};
+  class AllowsHoistingCheckClassBit :
+      public BitField<bool, kAllowsHoistingCheckClassBit, 1> {};  // NOLINT
 
   void set_name(const String& value) const;
   void set_kind(RawFunction::Kind value) const;
   void set_is_static(bool value) const;
   void set_is_const(bool value) const;
   void set_is_external(bool value) const;
   void set_parent_function(const Function& value) const;
   void set_owner(const Object& value) const;
   RawFunction* implicit_closure_function() const;
   void set_implicit_closure_function(const Function& value) const;
@@ skipping 4673 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_