Remember all deopt reasons in ic_data, not just the last one.

runtime/vm/raw_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_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/token.h"
@@ skipping 1003 matching lines @@
     intptr_t data_length = num_vars * (sizeof(VariableDesc)/kWordSize);
     return reinterpret_cast<RawObject**>(&ptr()->data_[data_length - 1]);
   }
 };
 
 
 class RawICData : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(ICData);
 
   RawObject** from() {
-    return reinterpret_cast<RawObject**>(&ptr()->function_);
+    return reinterpret_cast<RawObject**>(&ptr()->owner_);
   }
-  RawFunction* function_;      // Parent/calling function of this IC.
+  RawFunction* owner_;         // Parent/calling function of this IC.
   RawString* target_name_;     // Name of target function.
   RawArray* args_descriptor_;  // Arguments descriptor.
   RawArray* ic_data_;          // Contains class-ids, target and count.
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->ic_data_);
   }
-  intptr_t deopt_id_;          // Deoptimization id corresponding to this IC.
-  intptr_t num_args_tested_;   // Number of arguments tested in IC.
-  uint8_t deopt_reason_;       // Last deoptimization reason.
-  uint8_t is_closure_call_;    // 0 or 1.
+  int32_t deopt_id_;     // Deoptimization id corresponding to this IC.
+  uint32_t state_bits_;  // Number of arguments tested in IC, deopt reasons,
+                         // is closure call, JS warning issued.
 };
 
 
 class RawMegamorphicCache : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(MegamorphicCache);
 
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->buckets_);
   }
   RawArray* buckets_;
@@ skipping 789 matching lines @@
   // Make sure this is updated when new TypedData types are added.
   ASSERT(kTypedDataInt8ArrayViewCid == kTypedDataInt8ArrayCid + 14);
   ASSERT(kExternalTypedDataInt8ArrayCid == kTypedDataInt8ArrayViewCid + 15);
   ASSERT(kNullCid == kExternalTypedDataInt8ArrayCid + 14);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_