WIP SharedArrayBuffer implementation

src/accessors.cc

Index: src/accessors.cc
diff --git a/src/accessors.cc b/src/accessors.cc
index 50df0dd382ad31626c4fc274168e57a4c8131afc..252b809a18da5af564142dba4c3d32b89440aa8e 100644
--- a/src/accessors.cc
+++ b/src/accessors.cc
@@ -81,6 +81,7 @@ bool Accessors::IsJSObjectFieldAccessor(Handle<Map> map, Handle<Name> name,
         CheckForName(name, isolate->factory()->length_string(),
                      JSArray::kLengthOffset, object_offset);
     case JS_ARRAY_BUFFER_TYPE:
+    case JS_SHARED_ARRAY_BUFFER_TYPE:
       return CheckForName(name, isolate->factory()->byte_length_string(),
                           JSArrayBuffer::kByteLengthOffset, object_offset);
     default:
@@ -101,6 +102,7 @@ bool Accessors::IsJSArrayBufferViewFieldAccessor(Handle<Map> map,
 
   switch (map->instance_type()) {
     case JS_TYPED_ARRAY_TYPE:
+    case JS_SHARED_TYPED_ARRAY_TYPE:
       // %TypedArray%.prototype is non-configurable, and so are the following
       // named properties on %TypedArray%.prototype, so we can directly inline
       // the field-load for typed array maps that still use their