Make Gold more like Core.
Make Gold more like Core.

Summary:Adding padding for Android was wrong, instead, we should have
used `std::aligned_storage`.

Reviewed By: fugalh

Differential Revision: D2934566

fb-gh-sync-id: f541b89309be70791fced48f63b6b5aecc49bfbb
shipit-source-id: f541b89309be70791fced48f63b6b5aecc49bfbb

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