perf beauty: Add CLEAR_SIGHAND support for clone's flags arg

Add support for the recently added CLONE_CLEAR_SIGHAND flag.

This takes advantage of the copy of the uapi/linux/sched.h we have in
tools/include, which allows us to build tools/perf in older systems and
have the binary support printing that flag whenever that system gets its
kernel updated to one where this feature is present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Adrian Reber <areber@redhat.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org
Link: https://lkml.kernel.org/n/tip-1vnz497ubtu5oz16ygdcul0e@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/trace/beauty/clone.c

@@ -45,6 +45,7 @@ static size_t clone__scnprintf_flags(unsigned long flags, char *bf, size_t size,
 	P_FLAG(NEWPID);
 	P_FLAG(NEWNET);
 	P_FLAG(IO);
+	P_FLAG(CLEAR_SIGHAND);
 #undef P_FLAG
 
 	if (flags)