Fix column name where it starts with a backtick

mysql-test/r/sp.result:
  test for backticks
mysql-test/t/sp.test:
  test for backticks

mysql-test/r/sp.result

@@ -1649,3 +1649,8 @@ call p1();
 1
 drop procedure p1;
 drop table t1;
+create function `foo` () returns int return 5;
+select `foo` ();
+`foo` ()
+5
+drop function `foo`;

mysql-test/t/sp.test

@@ -1853,3 +1853,9 @@ call p1();
 drop procedure p1;
 drop table t1;
 
+#
+# backticks
+#
+create function `foo` () returns int return 5;
+select `foo` ();
+drop function `foo`;

sql/sql_yacc.yy

@@ -3609,8 +3609,12 @@ select_item:
 	      YYABORT;
 	    if ($4.str)
 	      $2->set_name($4.str,$4.length,system_charset_info);
-	    else if (!$2->name)
-	      $2->set_name($1,(uint) ($3 - $1), YYTHD->charset());
+	    else if (!$2->name) {
+	      char *str = $1;
+	      if (str[-1] == '`')
+	        str--;
+	      $2->set_name(str,(uint) ($3 - str), YYTHD->charset());
+	    }
 	  };
 
 remember_name: