[RFA] Patch for PR debug/40109

[Jason Merrill]

> +      /* Use the DIE of the containing namespace as the parent DIE of
> +         the type description DIE we want to generate.  */
> +      if (TYPE_CONTEXT (type)
> +	  && TREE_CODE (TYPE_CONTEXT (type)) == NAMESPACE_DECL)
> +	context_die = lookup_decl_die (TYPE_CONTEXT (type));

Using TYPE_CONTEXT is wrong for a typedef; we need to use DECL_CONTEXT 
of the typedef decl.

Jason