Move logic for hidden properties into the JSObject.

Move logic for hidden properties into the JSObject.

Previously, the logic using the hidden properties backing object was
spread accross use sites. Now it's all contained in JSObject, with
only simple accessors available.
Also change the backing object to be a StringDictionary rather than a JSObject.
There's still room for improvement by making a hash-table that don't
store property details as well.

Committed: http://code.google.com/p/v8/source/detail?r=9510

[Rico, 2011-09-27 13:40:40]

http://codereview.chromium.org/8050013/diff/1/src/handles.h
File src/handles.h (right):

http://codereview.chromium.org/8050013/diff/1/src/handles.h#newcode272
src/handles.h:272: Handle<Object>value);
space before value

http://codereview.chromium.org/8050013/diff/1/src/objects.cc
File src/objects.cc (right):

http://codereview.chromium.org/8050013/diff/1/src/objects.cc#newcode3340
src/objects.cc:3340: object = JSObject::cast(proxy_parent);
What do we expect to get out of setting the object pointer here?
As I see it we don't use object anywhere, and it is just a pointer to this that
we change to a pointer to the proxy_parent. What am I missing here?

[Lasse Reichstein, 2011-09-28 07:28:26]

http://codereview.chromium.org/8050013/diff/1/src/objects.cc
File src/objects.cc (right):

http://codereview.chromium.org/8050013/diff/1/src/objects.cc#newcode3340
src/objects.cc:3340: object = JSObject::cast(proxy_parent);
Whoops.
I can understand you can't see the reason, since it makes no sense.
I should ofcourse be using "object" instead of the implicit "this" in calls
below. Fixing.

[Rico, 2011-09-28 08:59:56]

LGTM

http://codereview.chromium.org/8050013/diff/5001/src/objects.cc
File src/objects.cc (right):

http://codereview.chromium.org/8050013/diff/5001/src/objects.cc#newcode3460
src/objects.cc:3460: MaybeObject* store_result =
If we have fast properties shouldn't we set this on the descriptorarray here?
With the current code will we ever hit that case?

http://codereview.chromium.org/8050013/diff/5001/src/objects.h
File src/objects.h (right):

http://codereview.chromium.org/8050013/diff/5001/src/objects.h#newcode1585
src/objects.h:1585: // Sets a hidden property on this object. Returns this
object if successfull,
remove one l from successfull

[Lasse Reichstein, 2011-09-28 10:21:41]

http://codereview.chromium.org/8050013/diff/5001/src/objects.cc
File src/objects.cc (right):

http://codereview.chromium.org/8050013/diff/5001/src/objects.cc#newcode3460
src/objects.cc:3460: MaybeObject* store_result =
The SetPropertyPostInterceptor will put the new property in the descriptor array
if there is room in the object.

I have no idea whether that will actually happen in practice, since the hidden
properties are used through the api, so we don't know the use-cases.