MFC r253810

grep -i does not work for simple patterns and single byte locales, like
	LANG=ru_RU.KOI8-R grep -i <some single KOI8-R letter>
Fix it.

Approved by:    re (delphij,kib)
MFC r253818:

Fix zfs send -D hang after processing requiring a CTRL+C to interrupt due to
pthread_join prior to fd close.

Approved by:	re (delphij)
Merge remote-tracking branch 'upstream-github/stable/9' into stable/9