re PR c++/66289 ("error: ambiguous template instantiation" with partial specialization defined in terms of alias template)

	PR c++/66289
	* cp-tree.h (TEMPLATE_DECL_COMPLEX_ALIAS_P): New.
	* pt.c (push_template_decl_real): Set it.
	(dependent_alias_template_spec_p): Use it.
	(dependent_type_p_r): Use dependent_alias_template_spec_p.
	(uses_all_template_parms_data, uses_all_template_parms_r)
	(complex_alias_template_p): New.
	(get_template_parm_index): Handle BOUND_TEMPLATE_TEMPLATE_PARM.

From-SVN: r224331