When cross building to android r15c (and older versions) on Fedora 26
we notice these:

/opt/android-ndk-r15c/platforms/android-24/arch-arm/usr/include/sys/cdefs.h:332:0: note: this is the location of the previous definition

For __aligned, __packed and __noreturn, so guard those with ifdefs to
avoid drowning useful warnings in these.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d7w3fa9c22dtmrwbedos6ie1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To have a more compact way to ask the compiler to use a specific
alignment, making tools/ look more like kernel source code.

Cc: Adrian Hunter <adrian.hunter@intel.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: http://lkml.kernel.org/n/tip-8jiem6ubg9rlpbs7c2p900no@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To have a more compact way to ask the compiler to not insert alignment
paddings in a struct, making tools/ look more like kernel source code.

Cc: Adrian Hunter <adrian.hunter@intel.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: http://lkml.kernel.org/n/tip-byp46nr7hsxvvyc9oupfb40q@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To have a more compact way to ask the compiler not to inline a function
and to make tools/ source code look like kernel code.

Cc: Adrian Hunter <adrian.hunter@intel.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: http://lkml.kernel.org/n/tip-bis4pqxegt6gbm5dlqs937tn@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To have a more compact way to ask the compiler to perform scanf like
argument validation.

Cc: Adrian Hunter <adrian.hunter@intel.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: http://lkml.kernel.org/n/tip-yzqrhfjrn26lqqtwf55egg0h@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To have a more compact way to ask the compiler to perform printf like
vargargs validation.

v2: Fixed up build on arm, squashing a patch by Kim Phillips, thanks!

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-dopkqmmuqs04cxzql0024nnu@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To have a more compact way to specify that a function doesn't return,
instead of the open coded:

	__attribute__((noreturn))

And use it instead of the tools/perf/ specific variation, NORETURN.

Cc: Adrian Hunter <adrian.hunter@intel.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: http://lkml.kernel.org/n/tip-l0y144qzixcy5t4c6i7pdiqj@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Will be used to adopt the more stringent version of ARRAY_SIZE(), the
one in the kernel sources.

Cc: Adrian Hunter <adrian.hunter@intel.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: http://lkml.kernel.org/n/tip-d85dpvay1hoqscpezlntyd8x@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

From the kernel, get the gcc one and provide the fallback so that we can
continue build with other compilers, such as with clang.

Will be used by tools/arch/x86/include/asm/cmpxchg.h.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-pecgz6efai4a9euuk4rxuotr@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To match the kernel headers structure, setting up things that are
specific to gcc or to some specific version of gcc.

It gets included by linux/compiler.h when gcc is the compiler being
used.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fabcqfq4asodq9t158hcs8t3@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>