This change improves performance for the common case of
Object.getOwnPropertyDescriptor by up 3x-4x, where we just
return a property descriptor object for a regular data or
accessor property.

CQ_INCLUDE_TRYBOTS=tryserver.chromium.win:win_chromium_rel_ng
R=yangguo@chromium.org

Committed: https://crrev.com/ffa9e82235b20c523ebb1151c6196bc6232296b9
Cr-Commit-Position: refs/heads/master@{#33398}

Review URL: https://codereview.chromium.org/1607943003

Cr-Commit-Position: refs/heads/master@{#33415}