MFC r240829: remove cache entries associated with the source and the target of rename()

MFC slacker:	pjd
MFC r250149: In case ZFS doesn't use UMA for buffers there's no need to waste memory
MFC r253819: MFV r253781 + r253871: 3894 zfs should not allow snapshot of inconsistent dataset

MFC slacker:	delphij
MFC r253820: MFV r253782: 3888 zfs recv -F should destroy any snapshots
created since the incremental source

MFC slacker:	delphij