(build_trtable): Don't allocate the trtable until state->word_trtable is known. ...

(build_trtable): Don't allocate the trtable until state->word_trtable is known.  Don't hardcode UINT_BITS iterations on each bitset item.

(match_ctx_init, match_ctx_clean,
match_ctx_free, match_ctx_free_subtops,
match_ctx_add_entry, search_cur_bkref_entry,
match_ctx_clear_flag, match_ctx_add_subtop,
match_ctx_add_sublast, sift_ctx_init,
re_search_internal, re_search_2_stub, re_search_stub,
re_copy_regs, acquire_init_state_context,
prune_impossible_nodes, check_matching,
check_halt_node_context, check_halt_state_context
update_regs, proceed_next_node, push_fail_stack,
pop_fail_stack, set_regs, free_fail_stack_return,
sift_states_iter_mb, sift_states_backward
update_cur_sifted_state, add_epsilon_src_nodes,
sub_epsilon_src_nodes, check_dst_limits,
check_dst_limits_calc_pos, check_subexp_limits,
sift_states_bkref, clean_state_log_if_need,
merge_state_array, transit_state,
check_subexp_matching_top, transit_state_sb,
transit_state_mb, transit_state_bkref,
get_subexp, get_subexp_sub, find_subexp_node,
check_arrival, check_arrival_add_next_nodes,
find_collation_sequence_value, check_arrival_expand_ecl,
check_arrival_expand_ecl_sub, expand_bkref_cache,
build_trtable, check_node_accept_bytes, extend_buffers,
group_nodes_into_DFAstates, check_node_accept): Likewise.