MFreleng/8.4 r251256 (by hrs):
Update description of logical CPU handling in the latest releases and
remove obsolete sysctl variable machdep.hlt_logical_cpus.

MFC after:	3 days
When purging per-CPU UMA caches do not return empty buckets into the global
full bucket cache to not trigger assertion if allocation happen before that
global cache get purged.
If check_deferred_signal() execution needs binding of PLT symbol,
unlocking the rtld bind lock results in the processing of ast and
recursing into the check_deferred_signal().  Nested execution of
check_deferred_signal() delivers the signal to user code and clears
si_signo.  On return, top-level check_deferred_signal() frame
continues delivering the same signal one more time, but now with zero
si_signo.

Fix this by adding a flag to indicate that deferred delivery is
running, so check_deferred_signal() should avoid doing anything. Since
user signal handler is allowed to modify the passed machine context to
make return from the signal handler to cause arbitrary jump, or do
longjmp(). For this case, also clear the flag in thr_sighandler(),
since kernel signal delivery means that nested delivery code should
not run right now.

Reported by:	Vitaly Magerya <vmagerya@gmail.com>
Reviewed by:	davidxu, jilles
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
gcc: Bring updates from Google's enhanced gcc-4.2.1.

Google released and enhanced version of gcc-4.2.1 plus their local
patches for Android[1].

The patches are owned by Google and the license hasn't been changed
from  the original GPLv2. We are only bringing a subset of the
available patches that may be helpful in FreeBSD. Changes specific
to android are not included.

From the README.google file[1].

Patches applied to google_vendor_src_branch/gcc/gcc-4.2.1:

gcc/Makefile.in
gcc/c-common.c
gcc/c-common.h
gcc/c-opts.c
gcc/c-typeck.c
gcc/cp/typeck.c
gcc/doc/invoke.texi
gcc/flags.h
gcc/opts.c
gcc/tree-flow.h
gcc/tree-ssa-alias-warnings.c
gcc/tree-ssa-alias.c

 Backport of -Wstrict-aliasing from mainline.
  Silvius Rus <rus@google.com>

gcc/coverage.c:
  Patch coverage_checksum_string for PR 25351.
  Seongbae Park <spark@google.com>
  Not yet submitted to FSF.

gcc/c-opts.c
gcc/c-ppoutput.c
gcc/c.opt
gcc/doc/cppopts.texi
libcpp/Makefile.in
libcpp/directives-only.c
libcpp/directives.c
libcpp/files.c
libcpp/include/cpplib.h
libcpp/init.c
libcpp/internal.h
libcpp/macro.c
  Support for -fdirectives-only.
  Ollie Wild <aaw@google.com>.
  Submitted to FSF but not yet approved.

libstdc++-v3/include/ext/hashtable.h
  http://b/742065
  http://b/629994
  Reduce min size of hashtable for hash_map, hash_set from 53 to 5

libstdc++-v3/include/ext/hashtable.h
  http://b/629994
  Do not iterate over buckets if hashtable is empty.

gcc/common.opt
gcc/doc/invoke.texi
gcc/flags.h
gcc/gimplify.c
gcc/opts.c
  Add Saito's patch for -finstrument-functions-exclude-* options.

gcc/common.opt
gcc/doc/invoke.texi
gcc/final.c
gcc/flags.h
gcc/opts.c
gcc/testsuite/gcc.dg/Wframe-larger-than.c
  Add a new flag -Wframe-larger-than- which enables a new warning
  when a frame size of a function is larger than specified.
  This patch hasn't been integrated into gcc mainline yet.

gcc/tree-vrp.c
  Add a hack to avoid using ivopts information for pointers starting
  at constant values.

Reference:

[1]
https://android.googlesource.com/toolchain/gcc/+/master/gcc-4.2.1/

Obtained from:	Google Inc.
MFC after:	3 weeks
Get rid of the CONCAT macro.
Limit the large page size to 16MB for now.

MFC after:	1 week
Save and restore the trap vectors when doing OF calls on pSeries machines.

It turned out that on pSeries machines the call into OF modified the trap
vectors and this made further behaviour unpredictable.

With this commit I'm now able to boot multi user on a network booted
environment on my IntelliStation 285. This is a POWER5+ machine.

Discussed with:		nwhitehorn
MFC after:	1 week
gcc: Missing makefile changes for r258501.

pointyhat:	me
[automated] Merge in upstream-github/master