XPreverse()
  Reverse a String.
------------------------------------------------------------------------------

   Function:   XPreverse()

               XPreverse() will reverse the string completely. As an addition
               to the already extended set of string functions of Clipper,
               I didn't want to leave this one out.
               XPreverse() is written in Assembly.

   Syntax:     XPreverse(<cStr>) --> cReversedStr

   Arguments:  <cStr> is the string to reverse. Memos and strings
               up to any length will be converted.

   Returns:    The string, properly reversed.

   Usage:      ? XPreverse('Pepijn')            /* returns njipeP */
               ? XPreverse(XPreverse('Smits'))  /* returns Smits */