message: Fix some typos in comments in alignment.h
diff: #include <cstddef> // For `std::size_t` and `std::max_align_t`.
  #if __cplusplus >= 201103L
  - #include <type_traits> // For `std::alignment_of`.
  + #include <type_traits> // For `std::alignment_of` and `std::aligned_storage`.
  #endif
  namespace thrust
  @@ -155,7 +155,7 @@ struct aligned_type;
  ///
  /// The behavior is undefined if `Len` is 0 or `Align` is not a power of 2.
  ///
  -/// It is an implementation of C++11's \p std::alignment_of.
  +/// It is an implementation of C++11's \p std::aligned_storage.
  #if __cplusplus >= 201103L
  template <std::size_t Len, std::size_t Align>
  using aligned_storage = std::aligned_storage<Len, Align>;
  