With this change, we give different results for __alignof than MSVC, but
our record layout is compatible.
Some data member pointers also now have a size that is not a multiple of
their alignment.
Fixes PR18618.
Reviewers: majnemer
Differential Revision: http://llvm-reviews.chandlerc.com/D2669
llvm-svn: 200585
Reid Kleckner