Report rules which are never reduced by the parser: those hidden

by conflicts.
* src/LR0.c (save_reductions): Don't make the final state too
different: save its reduction (accept) instead of having a state
without any action (no shift or goto, no reduce).
Note: the final state is now a ``regular'' state, i.e., the
parsers now contain `reduce 0' as default reduction.
Nevertheless, since they decide to `accept' when yystate =
final_state, they still will not reduce rule 0.
* src/print.c (print_actions, print_reduction): Adjust.
* src/output.c (action_row): Track reduced rules.
(token_actions): Report rules never reduced.
* tests/conflicts.at, tests/regression.at: Adjust.

NEWS

@@ -8,7 +8,7 @@ Changes in version 1.49b:
      %glr-parser
   causes Bison to produce a Generalized LR (GLR) parser, capable of handling
   almost any context-free grammar, ambiguous or not.  The new declarations
-  %dprec and %merge on grammar rules allow parse-time resolution of 
+  %dprec and %merge on grammar rules allow parse-time resolution of
   ambiguities.  Contributed by Paul Hilfinger.
 
 * Output Directory
@@ -58,6 +58,10 @@ Changes in version 1.49b:
 * Useless rules, useless nonterminals
   They are now reported, as a warning, with their locations.
 
+* Rules never reduced
+  Rules that can never be reduced because of conflicts are now
+  reported.
+
 * Incorrect `Token not used'
   On a grammar such as