* call.c (NEED_TEMPORARY_P): New macro.
	(standard_conversion): Set it, for derived-to-base conversions.
	(reference_related_p): New function.
	(reference_compatible_p): Likewise.
	(convert_class_to_reference): Likewise.
	(direct_reference_binding): Likewise.
	(reference_binding): Rework for standards-compliance.
	(convert_like): Adjust accordingly.
	(maybe_handle_ref_bind): Simplify; the right conversion sequences
	are now built up in reference_binding.
	(initialize_reference): New function.
	* cp-tree.h (ICS_USER_FLAG): Document.
	(ICS_THIS_FLAG): Likewise.
	(ICS_BAD_FLAG): Likewise.
	(NEED_TEMPORARY_P): Likewise.
	(cp_lvalue_kind): New type.
	(real_lvalue_p): Return it.
	* error.c (dump_expr): Provide more accurate representation for
	AGGR_INIT_EXPRs.
	* init.c (expand_default_init): Do not try to perform implicit
	conversions for a brace-enclosed initializer.
	* search.c (lookup_conversions): Document.
	* tree.c (lvalue_p_1): Return a cp_lvalue_kind.  Calculate
	appropriately.
	(real_lvalue_p): Adjust accordingly.
	(lvalue_p): Likewise.
	(build_cplus_new): Don't allow the creation of an abstract class.
	* typeck.c (convert_for_initialization): Use initialize_reference.

From-SVN: r28221