* call.c (merge_conversion_sequences): New function.
	(build_conv): Set ICS_USER_FLAG for USER_CONVs.
	(convert_class_to_reference): Correct handling of second
	standard conversion sequence in a user-defined conversion
	sequence.
	(build_user_type_conversion_1): Use merge_conversion_sequences.
	* cp-tree.def: Add comments for CONV nodes.

	* g++.dg/init/ref3.C: New test.

From-SVN: r63930