* src/gram.h (item_number_t): New, the type of item numbers in

RITEM.  Note that it must be able to code symbol numbers as
positive number, and the negation of rule numbers as negative
numbers.
Adjust all dependencies (pretty many).
* src/reduce.c (rule): Remove this `short *' pointer: use
item_number_t.
* src/system.h (MINSHORT, MAXSHORT): Remove.
Include `limits.h'.
Adjust dependencies to using SHRT_MAX and SHRT_MIN.
(shortcpy): Remove.
(MAXTABLE): Move to...
* src/output.c (MAXTABLE): here.
(prepare_rules): Use output_int_table to output rhs.
* data/bison.simple, data/bison.c++: Adjust.
* tests/torture.at (Big triangle): Move the limit from 254 to
500.
* tests/regression.at (Web2c Actions): Ajust.
Trying with bigger grammars shows various phenomena: at 3000 (28Mb
of grammar file) bison is killed by my system, at 2000 (12Mb) bison
passes, but produces negative #line number, once fixed, GCC is
killed while compiling 14Mb, at 1500 (6.7 Mb of grammar, 8.2Mb of
C), it passes.
* src/state.h (state_h): Code input lines on ints, not shorts.

src/gram.h

@@ -109,11 +109,14 @@ extern int nsyms;
 extern int ntokens;
 extern int nvars;
 
-extern short *ritem;
+#define ITEM_NUMBER_MAX INT_MAX
+typedef int item_number_t;
+extern item_number_t *ritem;
 extern int nritems;
 
 extern int start_symbol;
 
+
 typedef struct rule_s
 {
   /* The number of the rule in the source.  It is usually the index in
@@ -125,7 +128,7 @@ typedef struct rule_s
   short number;
 
   symbol_t *lhs;
-  short *rhs;
+  item_number_t *rhs;
 
   /* This symbol provides both the associativity, and the precedence. */
   symbol_t *prec;
@@ -133,14 +136,14 @@ typedef struct rule_s
   /* This symbol was attached to the rule via %prec. */
   symbol_t *precsym;
 
-  short line;
+  int line;
   bool useful;
 
   const char *action;
-  short action_line;
+  int action_line;
 
   const char *guard;
-  short guard_line;
+  int guard_line;
 } rule_t;
 
 extern struct rule_s *rules;