Split GuardField into GuardFieldType and GuardFieldLength instructions.

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 667 matching lines @@
   RawArray* dependent_code_;
   RawSmi* guarded_list_length_;
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->guarded_list_length_);
   }
 
   intptr_t token_pos_;
   intptr_t guarded_cid_;
   intptr_t is_nullable_;  // kNullCid if field can contain null value and
                           // any other value otherwise.
+  // Offset to the guarded length field inside an instance of class matching
+  // guarded_cid_. Stored corrected by -kHeapObjectTag to simplify code
+  // generated on platforms with weak addressing modes (ARM, MIPS).
+  int8_t guarded_list_length_in_object_offset_;
+
   uint8_t kind_bits_;  // static, final, const, has initializer.
 };
 
 
 class RawLiteralToken : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(LiteralToken);
 
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->literal_);
   }
@@ skipping 1142 matching lines @@
   COMPILE_ASSERT(kTypedDataInt8ArrayViewCid == kTypedDataInt8ArrayCid + 14);
   COMPILE_ASSERT(kExternalTypedDataInt8ArrayCid ==
                  kTypedDataInt8ArrayViewCid + 15);
   COMPILE_ASSERT(kNullCid == kExternalTypedDataInt8ArrayCid + 14);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_