Merging r276215:

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r276215 | ericwf | 2016-07-20 17:56:42 -0600 (Wed, 20 Jul 2016) | 9 lines

[libunwind] Properly align _Unwind_Exception.

Summary: _Unwind_Exception is required to be double word aligned. Currently the struct is under aligned.

Reviewers: mclow.lists, compnerd, kledzik, emaste

Subscribers: emaste, cfe-commits

Differential Revision: https://reviews.llvm.org/D22543
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llvm-svn: 276462