The existing PropertyQueryCallback intercepts getOwnPropertyDescriptor, but
it returns only value and attributes, not the accessors. This
PropertyDescriptorCallback returns a descriptor similar to Ecma-262 6.2.4.

You can either set a PropertyQueryCallback or a PropertyDescriptorCallback,
but not both. When you set a callback for DefineProperty(), you can set a
PropertyDescriptorCallback but not a PropertyQueryCallback.

BUG=v8:5359

Review-Url: https://codereview.chromium.org/2311873002
Cr-Commit-Position: refs/heads/master@{#39279}