To pick up the changes in these csets:

  295bcca84916 ("linux/bits.h: add compile time sanity check of GENMASK inputs")
  3945ff37d2f4 ("linux/bits.h: Extract common header for vDSO")

To address this tools/perf build warning:

  Warning: Kernel ABI header at 'tools/include/linux/bits.h' differs from latest version at 'include/linux/bits.h'
  diff -u tools/include/linux/bits.h include/linux/bits.h

This clashes with usage of userspace's static_assert(), that, at least
on glibc, is guarded by a ifnded/endif pair, do the same to our copy of
build_bug.h and avoid that diff in check_headers.sh so that we continue
checking for drifts with the kernel sources master copy.

This will all be tested with the set of build containers that includes
uCLibc, musl libc, lots of glibc versions in lots of distros and cross
build environments.

The tools/objtool, tools/bpf, etc were tested as well.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes in this cset:

  95b980d62d52 ("linux/bits.h: make BIT(), GENMASK(), and friends available in assembly")

To address this tools/perf build warning:

  Warning: Kernel ABI header at 'tools/include/linux/bits.h' differs from latest version at 'include/linux/bits.h'
  diff -u tools/include/linux/bits.h include/linux/bits.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-1if3iga5r3di6oyddgxsr225@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

So that we reduce the difference of tools/include/linux/bitops.h to the
original kernel file, include/linux/bitops.h, trying to remove the need
to define BITS_PER_LONG, to avoid clashes with asm/bitsperlong.h.

And the things removed from tools/include/linux/bitops.h are really in
linux/bits.h, so that we can have a copy and then
tools/perf/check_headers.sh will tell us when new stuff gets added to
linux/bits.h so that we can check if it is useful and if any adjustment
needs to be done to the tools/{include,arch}/ copies.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-y1sqyydvfzo0bjjoj4zsl562@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>