Fix gcc build.

Sponsored by:	The FreeBSD Foundation
MFC after:	13 days
Fix spurious "child process X terminated with exit status 1" messages
from automountd(8).

MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Fix bug that made automount(8) never unmount stale autofs(5) mounts,
ie mounts for entries that were there in auto_master(5), and then
got removed.

MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Update patch-r274286-llvm-r201784-asm-dollar.diff, so
test/MC/AsmParser/macros.s is properly deleted when patching.
Pull in r221170 from upstream clang trunk (by Roman Divacky):

  Implement vaarg lowering for ppc32. Lowering of scalars and
  aggregates is supported. Complex numbers are not.

This adds va_args support for PowerPC (32 bit) to clang.

Reviewed by:	jhibbits
MFC after:	3 days
Differential Revision: https://reviews.freebsd.org/D1308
Add clang patch corresponding to r275759.
Clean up, reindent, add a special case for NIS / LDAP line

MFC after:	1 week
sh: Make sure output suitable as shell input is also printable.

Commands like 'export -p', 'set' and 'trap', and tracing enabled via 'set
-x' generate output suitable as shell input by adding quotes as necessary.

If there are control characters other than newline or invalid UTF-8
sequences, use $'...' and \OOO to display them safely.

The resulting output is not parsable by a strict POSIX.1-2008 shell but sh
from FreeBSD 9.0 and newer and many other shells can parse it.
Add a vigr(8) utility which does for /etc/group what vipw(8) does for
/etc/master.passwd.
Update clang patch for r275759 to use correct test cases.
Move ofw_cpu.c to sys/dev/ofw so that it can be used by other
architectures.

Differential Revision:	https://reviews.freebsd.org/D1307
Reviewed by:	jhibbits
MFV r275549:

Add a loader tunable, vfs.zfs.arc_meta_min, which controls how much metadata
ZFS should keep in ARC at minimum.

In arc_evict(), when doing recycle, take more factors into account by
applying the following policy:

  1. If no evictable data, evict metadata;
  2. If no evictable metadata, evict data;
  3. If we hit arc_meta_limit, evict metadata;
  4. If we haven't hit arc_meta_min, evict data;
  5* (Illumos only, not present in new FreeBSD code, yet) evict the oldest
     cached element from data and metadata.
     (FreeBSD) evict the data type specified by caller, which is the
     existing behavior.

Note that because of our splitted locks (implemented in r205231 to improve
scalability by reducing lock contention), implementing the fifth Illumos
behavior will not be cheap, so for now just implement the 1-4 and fall back
to current behavior for 5.

Illumos issue:
    5368 ARC should cache more metadata

MFC after:	2 months (assuming we didn't found better solution)
MFV r275550:

In addition to r273158, make the code in spa_sync() that checks if the
current TXG is a no-op TXG less fragile.

Illumos issue:
    5347 idle pool may run itself out of space

MFC after:	2 weeks
MFV r275551:

Remove "dbuf phys" db->db_data pointer aliases.

Use function accessors that cast db->db_data to the appropriate
"phys" type, removing the need for clients of the dmu buf user
API to keep properly typed pointer aliases to db->db_data in order
to conveniently access their data.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_leaf.c:
        In zap_leaf() and zap_leaf_byteswap, now that the pointer alias
        field l_phys has been removed, use the db_data field in an on
        stack dmu_buf_t to point to the leaf's phys data.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c:
        Remove the db_user_data_ptr_ptr field from dbuf and all logic
        to maintain it.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dbuf.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dir.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sa.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_micro.c:
        Modify the DMU buf user API to remove the ability to specify
        a db_data aliasing pointer (db_user_data_ptr_ptr).

cddl/contrib/opensolaris/cmd/zdb/zdb.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_diff.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_traverse.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_tx.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_bookmark.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_deadlist.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_deleg.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_destroy.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dir.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_prop.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_userhold.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sa.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_history.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_leaf.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_micro.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dataset.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dir.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zap_impl.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h:
        Create and use the new "phys data" accessor functions
        dsl_dir_phys(), dsl_dataset_phys(), zap_m_phys(),
        zap_f_phys(), and zap_leaf_phys().

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dataset.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dir.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zap_impl.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h:
        Remove now unused "phys pointer" aliases to db->db_data
        from clients of the DMU buf user API.

Illumos issue:
    5314 Remove "dbuf phys" db->db_data pointer aliases in ZFS

MFC after:	2 weeks
Resolve USB driver identification conflict.

Reported by:	Anish Mistry <amistry@am-productions.biz>
MFC after:	1 week
Regenerate usb.conf .

MFC after:	1 week
Eliminate fdt_data_verify(). The verification it proceed is wrong
disallowing us to encode 64-bit register numbers.

Discussed with:	nwhitehorn, andrew
Follow r275792 eliminating fdt_data_verify().
Add a facility for non-init process to declare itself the reaper of
the orphaned descendants.  Base of the API is modelled after the same
feature from the DragonFlyBSD.

Requested by:	bapt
Reviewed by:	jilles (previous version)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
Fix typo.