Also add additional tools and libraries useful/needed for
compiling some of the ./tools in the kernel source.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>

projects are still using it, but it's still on hub so no
impact.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>

This cherry-picks 120010cb1eea151d38a3e66f5ffc79a0c3110292 ("tools build:
Add test for sched_getcpu()") which replaces a #ifdef based test with
a proper test for the sched_getcpu() function. The macro based condition
does not work on Alpine as it is conditional on GLIBC.

For 4.9 the cherry-pick needed some manual adjustment and also required
commit ef2c3e76d98dfb69a46d870b47656e8e5bac6e2b ("perf jit: Avoid returning
garbage for a ret variable")

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>

The perf utility is somewhat kernel specific so might as well
compile it when we compile the kernel. The resulting binary
is statically linked (and stripped for size) and is added the
resulting kernel packages.

Although we add alpine packages such as libunwind and other,
it seems that the config detection code for perf/tools does
not detect them.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>

Extract the perf binary from the kernel package and create
a new perf package for each kernel. The perf package uses the
same tags as the kernel package and only contains the perf
binary under /usr/bin. The perf package can be added to the
init section or included as a stage in a multi-stage build
for other packages.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>