[libcxxabi] Do not align field unwindHeader when building for ARM EHABI.

For ARM EHABI, _Unwind_Exception is an alias of _Unwind_Control_Block,
which is not aligned, so we shouldn't align unwindHeader either.

rdar://problem/25364625

git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@302981 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed