MFC r259088: Vendor import nvi-2.1.2-c80f493b038 a multikey mapping fix

PR:	bin/182463
MFC	r267875:

4251 libdtrace leaks open file handles

Illumos commit:		93ed8d0d4b068b95d0bb50d57bb854df462a8485
			(partial)
Reference:
https://www.illumos.org/issues/4251

Discussed with:	Robert Mustacchi
Obtained from:	Illumos
MFC	r269015:
fparseln(3): Update from NetBSD sources.

-fix a condition so that fparseln() doesn't report spurious empty lines
 eg after 2 comment lines, or on EOF after a single comment line
-no escape character means no escaped characters

modify the previous fix so that no pointless realloc()s are done in
the case of multiple empty continuation lines, and comment the code
to make the logics obvious.

fparseln is now part of libc in NetBSD so this changes the previous
revision numbering.

Obtained from:	NetBSD (CVS Rev. 1.6-1.7)
MFC	r269695:
Const-ify character string

Obtained from:  Apple Inc. (Libc 997.90.3)
MFC after:	3 days
MFC	r269901:
Minor style tweaks.

Obtained from:	OpenBSD (CVS rev. 1.7)
MFC	r269953:
Use "NO NAME" as the default unnamed label.

Microsoft recommends avoiding the use of spaces in the
string structures for FAT. Unfortunately they do just
that by default in the case of unlabeled filesystems.

Follow the default MS behavior to avoid confusion in
common tools like file(1). This was actually the
default behavior before r203868.

Obtained from:	NetBSD (CVS rev. 1.39)
MFC	r268924:
Update fflush(3) to return success on a read-only stream.

This is done for compliance with SUSv3. The changes cause
no secondary effects in the gnulib tests (we pass them).

Obtained from:	Apple Inc. (Libc 997.90.3 with changes)
Reviewed by:	bde
Phabric:	D440
MFC r269908:
Style.
MFC r269909:
Add a knob LIBPTHREAD_BIGSTACK_MAIN, which instructs libthr to leave
the whole RLIMIT_STACK-sized region of the kernel-allocated stack as
the stack of main thread.
MFC r269669:

 Split up sys_ktimer_getoverrun() into a sys_ and a kern_ variant
 and export the kern_ version needed by an upcoming linuxolator change.

 Sponsored by:	DARPA,AFRL
MFC r269583:

 Provide -o vers= support for mount_nfs.

 Our mount_nfs does use -o nfsv<2|3|4> or -2 or -3 to specify the version.
 OSX (these days), Solaris, and Linux use -o vers=<2,3,4>.

 With the upcoming autofs support we can make a lot of (entrerprisy) setups
 getting mount options from LDAP just work by providing -o vers= compatibility.

 Reviewed by:	wblock, bjk (man page), rmacklem, emaste
 Sponsored by:	DARPA,AFRL
PR:		192379
MFC r259884:

 Correct warnings comparing unsigned variables < 0 constantly reported
 while building kernels.  All instances removed are indeed unsigned so
 the expressions could not be true.
MFC r259885:

 As constantly reported during kernel compilation, m_buflen is unsigned so
 can never be < 0.  Remove the expression, which can never be true.
MFC r259916:

 Use feature_present(3) to determine whether to open an INET or an
 INET6 socket when needed to allow pfctl to work on noinet and noinet6
 kernels (and try to provide a fallback using AF_LINK as best effort).
 Adjust the Makefile to also respect relevant src.conf(5) options
 for compile time decisions on INET and INET6 support.

 Reviewed by:	glebius (no objections)
MFC r259886:

 Bite the bullet and start removing the first compile time warnings
 by removing unsued file local functions and then unused callees.
 A lot more warnings to resolve but someone had to break the ice.

 X-Comment:	I am not the new maintainer; chime in, it's ours.
MFC r261525:

 Print the MD5 signature information introduced in r221023 (head) in the
 TCP statistics output.
MFC r264539:

 When switching variables to flags in r243185 a few cases were missed.
 After r263152 (in head) this leaves unused variables if route(8) is
 compiled without INET support.
 Switch the remaining variable accesses to flags and remove now obsolete
 variables.

 Reviewed by:	glebius
MFC r266596:

 Move the tcp_fields_to_host() and tcp_fields_to_net() (inline)
 functions to the tcp_var.h header file in order to avoid further
 duplication with upcoming commits.

 Reviewed by:	np
MFC r266597:

 Remove the prototypes for things that are no longer file local but were
 moved to the header file.

 Was suppoed to be MFCed with: r266596
 Pointy hat to:	bz
MFC r266606:

 Only do a ports check if this is a NAT-T SA.  Otherwise other
 lookups providing ports may get unexpected results.