Allow property indexes to refer to slots inside the object header.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index ffa5283077cf51c7b33d6f85901452315df2070c..089a92457e7eb8c52dc82a63d0b44e1ffe87bbe3 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1084,11 +1084,11 @@ bool Genesis::InitializeGlobal(Handle<GlobalObject> inner_global,
     LookupResult lookup(isolate);
     result->LocalLookup(heap->callee_symbol(), &lookup);
     ASSERT(lookup.IsField());
-    ASSERT(lookup.GetFieldIndex() == Heap::kArgumentsCalleeIndex);
+    ASSERT(lookup.GetFieldIndex().FieldIndex() == Heap::kArgumentsCalleeIndex);
 
     result->LocalLookup(heap->length_symbol(), &lookup);
     ASSERT(lookup.IsField());
-    ASSERT(lookup.GetFieldIndex() == Heap::kArgumentsLengthIndex);
+    ASSERT(lookup.GetFieldIndex().FieldIndex() == Heap::kArgumentsLengthIndex);
 
     ASSERT(result->map()->inobject_properties() > Heap::kArgumentsCalleeIndex);
     ASSERT(result->map()->inobject_properties() > Heap::kArgumentsLengthIndex);
@@ -1186,7 +1186,7 @@ bool Genesis::InitializeGlobal(Handle<GlobalObject> inner_global,
     LookupResult lookup(isolate);
     result->LocalLookup(heap->length_symbol(), &lookup);
     ASSERT(lookup.IsField());
-    ASSERT(lookup.GetFieldIndex() == Heap::kArgumentsLengthIndex);
+    ASSERT(lookup.GetFieldIndex().FieldIndex() == Heap::kArgumentsLengthIndex);
 
     ASSERT(result->map()->inobject_properties() > Heap::kArgumentsLengthIndex);