Changes in response to error report by S. Eken: GLR mode does not
(yyfill): New function to copy from stack tree into array
(yyuserAction): Modify to allow incremental move of semantic values
to rhs array when in GLR mode.
Define YYFILL to use in user-defined actions to fill semantic array
(yyresolveStates): Use X == NULL for pointers, not !X.