PR c++/12266
	* cp-tree.h (tsubst_flags_t): Add tf_conv.
	* class.c (standard_conversion): Pass tf_conv to
	instantiate_type.
	(resolve_address_of_overloaded_function): Do not call mark_used
	when just checking conversions.

	PR c++/12266
	* g++.dg/overload/template1.C: New test.

From-SVN: r71483