https://gcc.gnu.org/ml/gcc-patches/2017-10/msg01854.html
	Kill IDENTIFIER_LABEL_VALUE.
	* cp-tree.h (lang_identifier): Delete label_value slot.
	(IDENTIFIER_LABEL_VALUE, SET_IDENTIFIER_LABEL_VALUE): Delete.
	(struct named_label_hasher): Rename to ...
	(struct named_label_hash): ... here.  Reimplement.
	(struct language_function): Adjust x_named_labels.
	* name-lookup.h (struct cp_label_binding): Delete.
	(struct cp_binding_level): Delete shadowed_labels slot.
	* decl.c (struct named_label_entry): Add name and outer slots.
	(pop_label): Rename to ...
	(check_label_used): ... here.  Don't pop.
	(note_label, sort_labels): Delete.
	(pop_labels, pop_local_label): Reimplement.
	(poplevel): Pop local labels as any other decl. Remove
	shadowed_labels handling.
	(named_label_hash::hash, named_label_hash::equal): New.
	(make_label_decl): Absorb into ...
	(lookup_label_1): ... here.  Add making_local_p arg, reimplement.
	(lookup_label, declare_local_label): Adjust.
	(check_goto, define_label): Adjust.
	* lex.c (make_conv_op_name): Don't clear IDENTIFIER_LABEL_VALUE.
	* ptree.c (cxx_print_identifier): Don't print identifier binding.

From-SVN: r254087