re PR c++/57068 (gcc prints warning "ref-qualifiers only available with -std=c++0x or -std=gnu++0x" for operator&)

	PR c++/57068
	* decl.c (grokdeclarator): Warn about ref-qualifiers here.
	* parser.c (cp_parser_ref_qualifier_seq_opt): Not here.
	* error.c (maybe_warn_cpp0x): s/0x/11/.

From-SVN: r198730