r196892 - Implement DR1460: fix handling of default initializers in unions; don't allow

[Renato Golin]

Hi Richard,

Your commit is failing on our ARM buildbot:

http://lab.llvm.org:8011/builders/clang-native-arm-cortex-a15-arch/builds/374/steps/check-all/logs/Clang%3A%3Amember-init-anon-union.cpp

Although most ARM buildbots are failing due to a major cosmological
alignment, that is a genuine failure. ;)

cheers,
--renato