[class.mem.general] Fix data member definition to include anonymous union members#8502

tkoeppe merged 1 commit intocplusplus:maincplusplus/draft:mainfrom

hubert-reinterpretcast:ClassMemGeneral-AcknowledgeAnonUnionMembershubert-reinterpretcast/draft:ClassMemGeneral-AcknowledgeAnonUnionMembersCopy head branch name to clipboard