Revert most of MaybeUninit, except for the new API itself#54554

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RalfJung:maybe-uninit

Sep 29, 2018

Commits on Sep 29, 2018

Revert "Auto merge of #53508 - japaric:maybe-uninit, r=RalfJung"
RalfJung
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add MaybeUninit

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RalfJung
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