Merging r201843
    
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    r201843 | chandlerc | 2014-02-21 00:37:30 -0800 (Fri, 21 Feb 2014) | 4 lines
    
    Teach libc++ to use the compiler-provided C-compatible ::max_align_t
    rather than its own type for std::max_align_t. This is particularly
    relevant as the types may not be ABI compatible despite users expecting
    them to be.
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    llvm-svn: 209032