In the kernel's tools/perf/Makefile CFLAGS was previously hard coded to
contain "-I/usr/include/slang" to work with hosts that have
"/usr/include/slang/slang.h" as well as hosts that have
"/usr/include/slang.h". This path can cause compile warnings like:

  cc1: warning: '/usr/include/slang' doesn't exists.

  or

  cc1: warning: include location "/usr/include/slang" is unsafe for
  cross-compilation [-Wpoison-system-directories]

Then in some cases warnings become errors if WERROR is enabled hence
build errors.

In coordination with a kernel fix, we can fix this error for all
kernels by modifying the perf Makefile within the staged kernel
source.

Signed-off-by: Liang Li <liang.li@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>

Add in a workaround to avoid host infection detection build failures
from the slang include directory in perf. I'll defer to Bruce to
fix this properly but we need a workaround now as this is breaking
builds.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

Signed-off-by: Saul Wold <sgw@linux.intel.com>

ExtUtils::Embed ccopts is getting the host's -I/usr/local/include and
using it to compile perf, which results in a compilation error that
started appearing just recently.

This turns the code that makes use of ExtUtils::Embed off and simply
hard-codes NO_LIBPERL.

It does the same for LIBPYTHON while we're at it, since it probably
suffers from a similar underlying problem and just by chance hasn't
broken anything yet.

This will be re-enabled after I familiarize myself with the perf
recipe and am able to create a proper fix.

Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>