Check for SS_NBIO in so->so_state instead of sb->sb_flags in
soreceive_stream().

Differential Revision:	https://reviews.freebsd.org/D1299
Reviewed by:	bz, gnn
MFC after:	1 week
Correct elftoolchain strip(1) memory size calculation

Calculate the segment's memory size (p_memsz) using the virtual
addresses, not the file offsets. Otherwise padding preceeding SHT_NOBITS
sections may be excluded from the calculation, resulting in a segment
that is too small.

PR:		195653
Sponsored by:	The FreeBSD Foundation
MFV r275783:

Convert ARC flags to use enum.  Previously, public flags are defined in
arc.h and private flags are defined in arc.c which can lead to confusion
and programming errors.

Consistently use 'hdr' (when referencing arc_buf_hdr_t) instead of 'buf'
or 'ab' because arc_buf_t are often named 'buf' as well.

Illumos issue:
    5369 arc flags should be an enum
    5370 consistent arc_buf_hdr_t naming scheme

MFC after:	2 weeks
MFV r275784:

Plug a memory leak in libzfs.  In zfs_iter_bookmarks, an nvlist is allocated
before calling lzc_get_bookmarks, which allocates the nvlist again (and
overwrites the pointer to previously allocated list).

Illumos issue:
    5427 memory leak in libzfs when doing rollback

MFC after:	2 weeks
Properly sort Xr to silence mandoc warnings.

Differential Revision:	https://reviews.freebsd.org/D1314
Reviewed by:	wblock
MFC after:	1 Month
Use standard BSD license disclaimer text

Approved by:	benno, nwhitehorn