libperf: Add perf_cpu_map test

libperf: Add perf_cpu_map test

Add simple perf_cpu_map tests.

Committer testing:

One has to build it in the source tree, a limitation that should be
fixed in followup patches:

  $ make O=/tmp/build/perf -C tools/perf/lib
  make: Entering directory '/home/acme/git/perf/tools/perf/lib'
    LINK     /tmp/build/perf/libperf.so.0.0.1
    GEN      /tmp/build/perf/libperf.pc
  make: Leaving directory '/home/acme/git/perf/tools/perf/lib'
  $ make O=/tmp/build/perf -C tools/perf/lib  tests
  make: Entering directory '/home/acme/git/perf/tools/perf/lib'
    LINK     test-cpumap-a
  gcc: error: ../libperf.a: No such file or directory
  make[1]: *** [Makefile:22: test-cpumap-a] Error 1
  make: *** [Makefile:115: tests] Error 2
  make: Leaving directory '/home/acme/git/perf/tools/perf/lib'
  [acme@quaco perf]$ make -C tools/perf/lib
  make: Entering directory '/home/acme/git/perf/tools/perf/lib'
    HOSTCC   fixdep.o
    HOSTLD   fixdep-in.o
    LINK     fixdep
    CC       core.o
    CC       cpumap.o
    CC       threadmap.o
    CC       evsel.o
    CC       evlist.o
    CC       zalloc.o
    CC       xyarray.o
    CC       lib.o
    LD       libperf-in.o
    AR       libperf.a
    LINK     libperf.so.0.0.1
    GEN      libperf.pc
  make: Leaving directory '/home/acme/git/perf/tools/perf/lib'
  $ make O=/tmp/build/perf -C tools/perf/lib  tests
  make: Entering directory '/home/acme/git/perf/tools/perf/lib'
    LINK     test-cpumap-a
    LINK     test-cpumap-so
  running static:
  - running test-cpumap.c...OK
  running dynamic:
  - running test-cpumap.c...OK
  make: Leaving directory '/home/acme/git/perf/tools/perf/lib'
  $

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190721112506.12306-74-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>