* dwarf2out.c (gen_subprogram_die): Add DW_AT_reference or
	DW_AT_rvalue_reference attributes.

	* cp-objcp-common.c (cp_decl_dwarf_attribute): Handle DW_AT_reference
	and DW_AT_rvalue_reference.

	* g++.dg/debug/dwarf2/ref-2.C: New test.

From-SVN: r241492