PR c++/51641 - Lookup finds enclosing class member instead of template parameter

PR c++/51641 - Lookup finds enclosing class member instead of template parameter

gcc/cp/

	PR c++/51641
	* cp-tree.h (template_type_parameter_p): Declare new function.
	(parameter_of_template_p): Remove
	* pt.c (template_type_parameter_p): Define new function.
	(parameter_of_template_p): Remove.
	* name-lookup.c (binding_to_template_parms_of_scope_p): Don't rely
	on parameter_of_template_p anymore.  Compare the level of the
	template parameter to the depth of the template.

gcc/testsuite/

	PR c++/51641
	* g++.dg/lookup/hidden-class17.C: New test.

From-SVN: r183726