tools build: Add CFLAGS_REMOVE_* support

Adding support to remove options from final CFLAGS for both object file
and build target. It's now possible to remove CFLAGS options like:

CFLAGS_REMOVE_krava.o += -Wstrict-prototypes

Committer notes:

This comes from the kernel's kbuild infrastructure, the subset that is
supported in tools/ is being documented at tools/build/Documentation/Build.txt.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: William Cohen <wcohen@redhat.com>
Link: http://lkml.kernel.org/r/1478093749-5602-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools build: Build fixdep helper from perf and basic libs

Adding the fixdep target into the Makefile.include to ease up building of
fixdep helper, that needs to be built before we dive in to the build itself.
The user can invoke the fixdep target to build the helper.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1443004442-32660-8-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools build: Add Makefile.include

To ease up build framework code setup for users.

More shared code will be added in the following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1443004442-32660-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools build: Allow duplicate objects in the object list

It's sometimes useful to specify the object affiliation to multiple
config options like:

libperf-$(CONFIG_X86) += tsc.o
libperf-$(CONFIG_AUXTRACE) += tsc.o

while the object itself is linked only once. Adding the support for this
and ignoring duplicate objects in the object list.

Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20150826130103.GF22670@krava.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools build: Add new build support

Adding new build framework into 'tools/build' to be used by tools.

There's no change for actual building at this point, it comes in the
next patches.

The idea and more details are explained in the
'tools/build/Documentation/Build.txt' file.

I adopted everything from the kernel build system, with some changes to
allow for multiple binaries build definitions.

While the kernel's build output is single image (forget modules) we need
to be able to build several binaries/libraries.

The basic idea is that sser provides 'Build' files with objects
definitions like:

perf-y += a.o
perf-y += b.o
libperf-y += c.o
libperf-y += d.o

and the build framework outputs files:

perf-in.o # a.o, b.o compiled in
libperf-in.o # c.o, d.o compiled in

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Cc: Alexis Berlemont <alexis.berlemont@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-fbj22h4av0otlxupwcmrxgpa@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>