During deterministic GLR operation, user actions should be able to

During deterministic GLR operation, user actions should be able to
influence the parse by changing yychar.  To make this easier to fix and
to make glr.c easier to evolve in general, don't maintain yytoken in
parallel with yychar; just compute yytoken when needed.
* tests/glr-regression.at (Incorrect lookahead during deterministic
GLR): Check that setting yychar in a user action has the intended
effect.
* data/glr.c (yyGLRStack): Remove yytokenp member.
(yyclearin): Don't set *yytokenp.
(yyprocessOneStack, yyreportSyntaxError, yyrecoverSyntaxError): Examine
yychar rather than *yytokenp to determine the current lookahead.
Compute yytoken locally when needed.
(yyparse): Likewise.  Remove the local yytoken that yytokenp used to
point to.

* doc/bison.texinfo (Bison Options): Remove stray sentence fragment
after `--report' documentation.