Remove uses of 'short int' and 'unsigned short int' in the parser generators.

Remove uses of 'short int' and 'unsigned short int' in the parser generators.

* src/LR0.c (allocate_itemsets, new_itemsets, save_reductions):
Use size_t, not int or short int, to count objects.
* src/closure.c (nritemset, closure): Likewise.
* src/closure.h (nritemset, closure): Likewise.
* src/nullable.c (nullable_compute): Likewise.
* src/print.c (print_core): Likewise.
* src/print_graph.c (print_core): Likewise.
* src/state.c (state_compare, state_hash): Likewise.
* src/state.h (struct state): Likewise.
* src/tables.c (default_goto, goto_actions): Likewise.

* src/gram.h (rule_number, rule): Use int, not short int.
* src/output.c (prepare_rules): Likewise.
* src/state.h (state_number, STATE_NUMBER_MAXIMUM, transitions,
errs, reductions): Likewise.
* src/symtab.h (symbol_number, SYMBOL_NUMBER_MAXIMUM, struct symbol):
Likewise.
* src/tables.c (vector_number, tally, action_number,
ACTION_NUMBER_MINIMUM): Likewise.
* src/output.c (muscle_insert_short_int_table): Remove.