length = (cycle + 1) * REGEXP_ONEOF (regexp)->regexps_num;
while (VEC_length (unit_usage_t, cycle_alt_unit_usages) < length)
VEC_safe_push (unit_usage_t, heap, cycle_alt_unit_usages, 0);
length = (cycle + 1) * REGEXP_ONEOF (regexp)->regexps_num;
while (VEC_length (unit_usage_t, cycle_alt_unit_usages) < length)
VEC_safe_push (unit_usage_t, heap, cycle_alt_unit_usages, 0);