MFV	r258381:

4251 libdtrace leaks open file handles

Illumos commit:		93ed8d0d4b068b95d0bb50d57bb854df462a8485
			(partial)
Reference:
https://www.illumos.org/issues/4251

Discussed with:	Robert Mustacchi
Obtained from:	Illumos
MFC after:	1 week