parse.y: move numbered parameter indexing to lexer.

mrbgems/mruby-compiler/core/parse.y

@@ -712,10 +712,6 @@ new_cvar(parser_state *p, mrb_sym sym)
 static node*
 new_nvar(parser_state *p, int num)
 {
-  if (p->nvars) {
-    int nvars = intn(p->nvars->car);
-    p->nvars->car = nint(nvars > num ? nvars : num);
-  }
   return cons((node*)NODE_NVAR, nint(num));
 }
 
@@ -6429,6 +6425,9 @@ parser_yylex(parser_state *p)
           if (nvar == -1) {
             yywarning(p, "numbered parameter used in inner block");
           }
+          else {
+            p->nvars->car = nint(nvar > n ? nvar : n);
+          }
           pylval.num = n;
           p->lstate = EXPR_END;
           return tNUMPARAM;