4110 panic while reaping htable_cache

Cherry pick from illumos-nexenta 9496f7c241d1d03b9c93db0eb5d1af7dd6db6639
re# 14230 panic while reaping htable_cache
OS-21 reset HAT_VICTIM flag when hat is moved to the end of kas.a_hat list
Reviewed by: Gordon Ross <Gordon.Ross@nexenta.com>
Reviewed by: Ilya Usvyatsky <Ilya.Usvyatsky@nexenta.com>