Arrange for the first typedef to an anonymous type in the same context
to be used as the linkage name for the type.
for gcc/cp/ChangeLog
* decl.c (name_unnamed_type): Split out of...
(grokdeclarator): ... this.
* decl.h (name_unnamed_type): Declare.
for libcc1/ChangeLog
* libcp1plugin.cc (plugin_build_decl): Call name_unnamed_type.
From-SVN: r246938