c++/6601: [parser] Parse error when using :: qualified name in template

[Jason Merrill]

>>>>> "Nathan" == Nathan Sidwell <nathan@codesourcery.com> writes:

> It might be nicer though to fiddle the grammar so that where
> 	PTYPENAME < SCOPED_NAME 
> appears (under whatever guise it happens to be), we also have the reduction
> 	PTYPENAME [ : error >
> 	   error ("did you mean '$1 < ::'?")

Sounds good to me.  Patch, anyone?

Jason