Merge tag 'perf-core-for-mingo-4.12-20170419' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core cleanups from Arnaldo Carvalho de Melo:

 - Introduce new header files out of the hodge-podge that util/util.h
   became, trying to disentangle the includes hell that all C projects
   end up growing. This should help in build times, as changes to
   seemingly unrelated files (util.h included tons of headers) won't
   trigger a rebuild of most object files.

 - Use equivalent facilities found in the kernel source code base
   originated tools/include/ header files, such as __stringify(),
   ARRAY_SIZE, that has extra checks (__must_be_array()), etc.

 - For that get some more files from the kernel sources, like
   include/linux/bug.h, some just with the bits needed at this time.

 - Use the headers where facilities declared in them are used, such
   as PRIxu(32,64) macros (inttypes.h), errno defines (errno.h), etc.

 - Remove various leftovers from the initial code base we copied from
   git.git: FLEX_ARRAY, etc.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>