tools include UAPI: Sync x86's syscalls_64.tbl and generic unistd.h to pick up clone3 and pidfd_open

  05a70a8e ("unistd: protect clone3 via __ARCH_WANT_SYS_CLONE3")
  8f3220a8 ("arch: wire-up clone3() syscall")
  7615d9e1 ("arch: wire-up pidfd_open()")

Silencing the following tools/perf build warnings

  Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h'
  diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
  Warning: Kernel ABI header at 'tools/perf/arch/x86/entry/syscalls/syscall_64.tbl' differs from latest version at 'arch/x86/entry/syscalls/syscall_64.tbl'
  diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl

Now 'perf trace -e pidfd*,clone*' will trace those syscalls as well as the
others with those prefixes.

  $ diff -u /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c.before /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c
  --- /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c.before	2019-07-26 12:24:55.020944201 -0300
  +++ /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c	2019-07-26 12:25:03.919047217 -0300
  @@ -344,5 +344,7 @@
        [431] = "fsconfig",
        [432] = "fsmount",
        [433] = "fspick",
  +     [434] = "pidfd_open",
  +     [435] = "clone3",
   };
  -#define SYSCALLTBL_x86_64_MAX_ID 433
  +#define SYSCALLTBL_x86_64_MAX_ID 435
  $

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-0isnnqxtr1ihz6p8wzjiy47d@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>