Split GuardField into GuardFieldType and GuardFieldLength instructions.

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index abd993375d13cc52958c7510f3a56ee4b172b951..ff1188b8c143a8eaf12ac77387c99fb6e35f4fc0 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -685,6 +685,8 @@ class RawField : public RawObject {
   intptr_t guarded_cid_;
   intptr_t is_nullable_;  // kNullCid if field can contain null value and
                           // any other value otherwise.
+  intptr_t guarded_list_length_in_object_offset_;

[Florian Schneider, 2014/05/28 14:57:36]

Make this smaller (int8_t or int16_t) so that the following byte does not make
the object larger by a whole word-size.

[Vyacheslav Egorov (Google), 2014/05/29 17:36:51]

Done.

+
   uint8_t kind_bits_;  // static, final, const, has initializer.
 };