MFC r257300:
Fix an off-by-one error when checking whether a given address is within
the extent of a symbol.
MFC r257670:
Modify the libproc breakpoint add/remove functions to stop the target
process if it has not already been stopped, since this is required for
ptrace(2) to work.

libdtrace does not seem to stop target processes before trying to remove
their breakpoints, so we were previously failing to remove the breakpoint
on r_debug_state() in rtld. This was causing processes to die with SIGTRAP
if they called dlopen(3) after dtrace(1) had detached.
MFC r240040 (rpaulo):
Make sure we visit both symbol sections even if one of them doesn't
exist. This makes it possible to dtrace some C++ programs like devd.

MFC r254177 (rpaulo):
Fix the return value when we found a symbol in .dynstr. This nasty bug was
preventing a lot of symbol lookups in dtruss -s, for example.
MFC r258000:
Consistently add the relocation offset only when the ELF type is not
ET_EXEC. This fixes several problems with the DTrace pid provider not
being able to match probes.
MFC r259973:

Tighten default restrictions for ntpd(8) server and provide a link
to NTP access restriction documentation.
MFC r259756:

Get rid of register keyword usage in gperf, it is totally obsolete for
C++, and this allows gperf to be compiled for C++11 without a warning
about it.
MFC r259825:

Remove unused static function adwccbstatus() from adw(4).

Reviewed by:	gibbs
MFC r259827:

Remove unused static const variable num_chip_names from aic79xx.c.

Reviewed by:	gibbs
MFC r259833:

Remove another unused static const variable num_chip_names, from
aic7xxx.c this time.

Noticed by:	pluknet
MFC r259839:

In sys/netinet/in_mcast.c, inm_is_ifp_detached() is only used whenever
KTR is defined, so put it between #ifdef KTR guards.  This avoids a
warning about a unused function if KTR is not enabled.
MFC r259840:

In sys/netinet6/in6_mcast.c, in6m_is_ifp_detached() is only used
whenever KTR is defined, so put it between #ifdef KTR guards.  This
avoids a warning about a unused function if KTR is not enabled.
MFC r259842:

Remove some unused static const strings under sys/rpc, which have never
been used since the initial commit (r177633).

MFC r259843:

Move a static const variable to the #if 0 part where it is only used.
(Note the #if 0 part has been inactive since the initial commit,
r177633, so maybe it should be removed altogether).
MFC r259869:

In sys/dev/mwl/if_mwl.c, put the static RD4() function under #ifdef
MWL_DEBUG guards, since it only used in DPRINTF statements.
MFC r259875:

In sys/kern/sched_ule.c, remove static function sched_both(), which is
unused since r232207.
MFC r259880:

In sys/dev/sym/sym_hipd.c, remove static functions sym_que_first(),
sym_que_last() and sym_remque_tail(), which are all unused since r53790.
MFC r259876:

In sys/kern/subr_witness.c, remove static function
witness_lock_order_key_empty(), which is unused since r181695.
MFC r259888:

Pull in r183971 from upstream llvm trunk:

  X86: cvtpi2ps is just an SSE instruction with MMX operands. It has no AVX
  equivalent.

  Give it the right register format so we can also emit it when AVX is enabled.

This should fix a "Cannot select: intrinsic %llvm.x86.sse.cvtpi2ps" fatal error
in clang while building the gnuradio port for amd64.

Reported by:	db
MFC r259892:

In sys/kern/vfs_mountroot.c, remove static function parse_isspace(),
which is unused since r214006.
MFC r259896:

In sys/dev/cxgb/common/cxgb_mc5.c, remove static function
dbgi_wr_addr3(), which is unused since r167514.
MFC r259897:

In sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c, remove static functions
mk_cpl_barrier_ulp(), mk_get_tcb_ulp() and mk_set_tcb_field_ulp(), which
are all unused since r237263.