// profile that event by storing a pointer to the lock in its "to be profiled
// upon unlock" field. If that field is already set, it uses the relative
// magnitudes to weight a random choice between itself and the other lock, with
// the loser's time being added to the "additional contention" field. Otherwise
// if the M's call stack buffer is occupied, it does the comparison against that

	numRegexp   int               // number of regexps allocated
	numRunes    int               // number of runes in char classes
	repeats     int64             // product of all repetitions seen
	height      map[*Regexp]int   // regexp height, for height limit check
	size        map[*Regexp]int64 // regexp compiled size, for size limit check
}

func (p *parser) newRegexp(op Op) *Regexp {
	re := p.free
	if re != nil {