Adding automated test for testing the build process.

To run it you need to be in perf directory or specify one with PERF
variable. It's also possible to specify optional Makefile to test via MK
variable.

Whole suite is executed twice, the second time with O=/tmp/xxx option
added.

To run the whole suite:
  $ make -f tests/make
  - make_pure: cd . && make -f Makefile
    test: test -x ./perf
  - make_clean_all: cd . && make -f Makefile clean all
    test: test -x ./perf
  - make_python_perf_so: cd . && make -f Makefile python/perf.so
    test: test -f ./python/perf.so
  - make_debug: cd . && make -f Makefile DEBUG=1
    test: test -x ./perf
  - make_no_libperl: cd . && make -f Makefile NO_LIBPERL=1
    test: test -x ./perf

You see command line for 'make_pure' test right away, and the output is
stored into 'make_pure' file.

To run simple test:
  $ make -f tests/make make_debug
  - make_debug: cd . && make -f Makefile DEBUG=1
    test: test -x ./perf

At this moment tests checks for successfull build and for existence of
several built files. Additional after-build checks could be added.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1369398928-9809-2-git-send-email-jolsa@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>