tools lib api: Adopt fdarray class from perf's evlist

The extensible file description array that grew in the perf_evlist class
can be useful for other tools, as it is not something that only evlists
need, so move it to tools/lib/api/fd to ease sharing it.

v2: Don't use {} like in:

 libapi_dirs:
	$(QUIET_MKDIR)mkdir -p $(OUTPUT){fs,fd}/

in Makefiles, as it will not work in some systems, as in ubuntu13.10.

v3: Add fd/*.[ch] to LIBAPIKFS_SOURCES (Fix from Jiri Olsa)

v4: Leave the fcntl(fd, O_NONBLOCK) in the evlist layer, remains to
    be checked if it is really needed there, but has no place in the
    fdarray class (Fix from Jiri Olsa)

v5: Remove evlist details from fdarray grow/filter tests. Improve it a
    bit doing more tests about expected internal state.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-kleuni3hckbc3s0lu6yb9x40@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 174c3ff..ac655b0 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -158,12 +158,12 @@
 		.func = test__switch_tracking,
 	},
 	{
-		.desc = "Filter fds with revents mask in a pollfd array",
-		.func = test__perf_evlist__filter_pollfd,
+		.desc = "Filter fds with revents mask in a fdarray",
+		.func = test__fdarray__filter,
 	},
 	{
-		.desc = "Add fd to pollfd array, making it autogrow",
-		.func = test__perf_evlist__add_pollfd,
+		.desc = "Add fd to a fdarray, making it autogrow",
+		.func = test__fdarray__add,
 	},
 	{
 		.func = NULL,