PR c++/51553
	* cp-tree.h (LOOKUP_LIST_INIT_CTOR): Rename from
	LOOKUP_NO_COPY_CTOR_CONVERSION.
	(add_list_candidates): Set it earlier.
	(add_candidates): Don't check explicit on ctors when it's set.
	(add_function_candidate): Check it even when LOOKUP_ONLYCONVERTING
	is set.

From-SVN: r182496