The comments of Action::ActOnCXXMemberDeclarator, Sema's implementation
of it, and the call sites in the parser, refer to an argument called
'LastInGroup'. This argument seems to have been killed during the
DeclGroup restructuring, which is a good thing, but the documentation
should be updated to reflect this. In particular, it should be
documented if the function now does return the recently created
declaration, because right now the code looks like it does, but the
comments say no. This is very confusing.
Can whoever did the restructuring (Doug, I think) please update the
relevant comments to document the current behavior of the function?