More compact string representation on 64 bit.

runtime/vm/raw_object.cc

Index: runtime/vm/raw_object.cc
diff --git a/runtime/vm/raw_object.cc b/runtime/vm/raw_object.cc
index f4a1bc17618dd1f7de376c95dd4a86f1ee78eac0..66fee3e09bd9dfc9d908e6f1470415df55d6b873 100644
--- a/runtime/vm/raw_object.cc
+++ b/runtime/vm/raw_object.cc
@@ -821,7 +821,9 @@ intptr_t RawOneByteString::VisitOneByteStringPointers(
     RawOneByteString* raw_obj,
     ObjectPointerVisitor* visitor) {
   ASSERT(!raw_obj->ptr()->length_->IsHeapObject());
+#if !defined(HASH_IN_OBJECT_HEADER)
   ASSERT(!raw_obj->ptr()->hash_->IsHeapObject());
+#endif
   intptr_t length = Smi::Value(raw_obj->ptr()->length_);
   return OneByteString::InstanceSize(length);
 }
@@ -831,7 +833,9 @@ intptr_t RawTwoByteString::VisitTwoByteStringPointers(
     RawTwoByteString* raw_obj,
     ObjectPointerVisitor* visitor) {
   ASSERT(!raw_obj->ptr()->length_->IsHeapObject());
+#if !defined(HASH_IN_OBJECT_HEADER)
   ASSERT(!raw_obj->ptr()->hash_->IsHeapObject());
+#endif
   intptr_t length = Smi::Value(raw_obj->ptr()->length_);
   return TwoByteString::InstanceSize(length);
 }