PR c++/64359
	* pt.c (iterative_hash_template_arg): Hash alias specializations
	differently from their TYPE_CANONICAL.
	(alias_template_specialization_p): Optimize.
	(template_args_equal): Optimize alias handling.
	(dependent_alias_template_spec_p): Only check innermost args.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@218995 138bc75d-0d04-0410-961f-82ee72b054a4