+/* Back up lexptr by yyleng and then to the rightmost occurrence of
+ character CH, case-folded (there must be one). WARNING: since
+ lexptr points to the next input character that Flex has not yet
+ transferred to its internal buffer, the use of this function
+ depends on the assumption that Flex calls YY_INPUT only when it is
+ logically necessary to do so (thus, there is no reading ahead
+ farther than needed to identify the next token.) */
+
+static void
+rewind_to_char (int ch)