bistromathic: use gettext for all the messages

[Akim Demaille]

commit b27bba5cedbe552b2a406e051de293c677c2b9a7
Author: Akim Demaille <akim.demaille@gmail.com>
Date:   Tue Jan 26 06:48:04 2021 +0100

    bistromathic: use gettext for all the messages
    
    * examples/c/bistromathic/parse.y: Add missing calls to _.

diff --git a/examples/c/bistromathic/parse.y b/examples/c/bistromathic/parse.y
index 5d5efabff..783155f9a 100644
--- a/examples/c/bistromathic/parse.y
+++ b/examples/c/bistromathic/parse.y
@@ -187,7 +187,7 @@ exp:
   {
     if ($r == 0)
       {
-        yyerror (&@$, uctx, "error: division by zero");
+        yyerror (&@$, uctx, _("error: division by zero"));
         YYERROR;
       }
     else
@@ -345,7 +345,7 @@ yylex (const char **line, YYSTYPE *yylval, YYLTYPE *yylloc,
 
       // Stray characters.
     default:
-      yyerror (yylloc, uctx, "syntax error: invalid character: %c", c);
+      yyerror (yylloc, uctx, _("syntax error: invalid character: %c"), c);
       return TOK_YYerror;
     }
 }