localize use of yyleng with lexical_feedback member function * lex.h, lex.ll (lexical_feedback::yyleng): New function. (lexical_feedback::handle_number, lexical_feedback::handle_identifier, lexical_feedback::handle_meta_identifier, lexical_feedback::handle_superclass_identifier): Use it.

--- a/libinterp/parse-tree/lex.h
+++ b/libinterp/parse-tree/lex.h
@@ -212,6 +212,8 @@
 
   char *flex_yytext (void);
 
+  int flex_yyleng (void);
+
   void do_comma_insert_check (void);
 
   int text_yyinput (void);