[clang] [Sema] Fix false positive warnings for misaligned member access (PR #150025)

[Erich Keane via cfe-commits]

https://github.com/erichkeane approved this pull request.

Minor preference for a better 'alias' name in the 1 section (or none at all), but otherwise this is fine to me.  I'm Ok either way.

https://github.com/llvm/llvm-project/pull/150025