perf tools: Move everything related to sys_perf_event_open() to perf-sys.h

And remove unneeded include directives from perf-sys.h to prune the
header dependency tree.

Fixup the fallout in places where definitions were being used without
the needed include directives that were being satisfied because they
were in perf-sys.h.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-7b1zvugiwak4ibfa3j6ott7f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/perf-sys.h

@@ -5,10 +5,17 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/syscall.h>
-#include <linux/types.h>
 #include <linux/compiler.h>
-#include <linux/perf_event.h>
-#include <asm/barrier.h>
+
+struct perf_event_attr;
+
+extern bool test_attr__enabled;
+void test_attr__ready(void);
+void test_attr__init(void);
+void test_attr__open(struct perf_event_attr *attr, pid_t pid, int cpu,
+		     int fd, int group_fd, unsigned long flags);
+
+#define HAVE_ATTR_TEST
 
 static inline int
 sys_perf_event_open(struct perf_event_attr *attr,