PATCH to pushtag for template crash

[Jason Merrill]

>>>>> Mark Mitchell <mark@markmitchell.com> writes:

> Jason, the patch disables debug-generation for *all* of these
> TYPE_DECLs, not just the template version.

This sounds very wrong; the debugging backends use those stub _decls to
control emitting debugging information for class types.  If you set
DECL_IGNORED_P on the stubs, none of the classes will have debugging
information emitted.

Jason