const strconv.stepPowerOfTen

3 uses

	strconv (current package)
		extfloat.go#L25: 	stepPowerOfTen  = 8
		extfloat.go#L196: 	i := (approxExp10 - firstPowerOfTen) / stepPowerOfTen
		extfloat.go#L213: 	return -(firstPowerOfTen + i*stepPowerOfTen), i