re PR c/47043 (allow deprecating enum values)

re PR c/47043 (allow deprecating enum values)

	PR c/47043
	* c-common.c (handle_deprecated_attribute): Allow CONST_DECL.

	* c-parser.c (c_parser_enum_specifier): Parse and apply enumerator
	attributes.

	* cp-tree.h (build_enumerator): Update declaration.
	* decl.c (build_enumerator): Add attributes parameter.  Call
	cplus_decl_attributes.
	* init.c (constant_value_1): Pass tf_none to mark_used.
	* parser.c (cp_parser_enumerator_definition): Parse attributes and
	pass them down to build_enumerator.
	* pt.c (tsubst_enum): Pass decl attributes to build_enumerator.
	* semantics.c (finish_id_expression): Don't warn_deprecated_use here.

	* doc/extend.texi (Enumerator Attributes): New section.
	Document syntax of enumerator attributes.

	* c-c++-common/attributes-enum-1.c: New test.
	* c-c++-common/attributes-enum-2.c: New test.
	* g++.dg/cpp0x/attributes-enum-1.C: New test.
	* g++.dg/cpp1y/attributes-enum-1.C: New test.

Co-Authored-By: Edward Smith-Rowland <3dw4rd@verizon.net>
From-SVN: r223527