re PR c++/10428 (struct <typedef'ed name> causes ICE in write_unscoped_name)

	PR c++/10428
	* g++.dg/parse/elab1.C: New test.

	PR c++/10428
	* decl.c (check_elaborated_type_specifier): New function, split
	out from ...
	(xref_tag): ... here.  Use the new function in more places.

From-SVN: r65956