MFC r265152 - Reintroduce priority for the TRIM ZIOs instead of using the "NOW" priority
MFC r265321 - Fix double fault panic when returning EOPNOTSUPP
MFC r269407 - Don't return ZIO_PIPELINE_CONTINUE from vdev_op_io_start methods

Sponsored by:	Multiplay
MFC r269974 - Added 4K quirks for Corsair Force GT and Samsung 840 SSDs

Sponsored by:	Multiplay