Add new header definitions from Linux 4.4 (plus older ptrace definitions).

This patch adds some new header definitions from Linux 4.4:

* MCL_ONFAULT is added to bits/mman.h / bits/mman-linux.h (this was
  already done for hppa).

* PTRACE_SECCOMP_GET_FILTER is added to sys/ptrace.h.  Along with it,
  the older PTRACE_GETSIGMASK and PTRACE_SETSIGMASK, added in Linux
  3.11 but missed at the time, are also added.

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).

	* bits/mman-linux.h [!MCL_CURRENT] (MCL_ONFAULT): New macro.
	* sysdeps/unix/sysv/linux/alpha/bits/mman.h (MCL_ONFAULT):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/mman.h (MCL_ONFAULT):
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/mman.h (MCL_ONFAULT):
	Likewise.
	* sysdeps/unix/sysv/linux/sys/ptrace.h (PTRACE_GETSIGMASK): New
	enum constant and macro.
	(PTRACE_SETSIGMASK): Likewise.
	(PTRACE_SECCOMP_GET_FILTER): Likewise.
	* sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h
	(PTRACE_GETSIGMASK): Likewise.
	(PTRACE_SETSIGMASK): Likewise.
	(PTRACE_SECCOMP_GET_FILTER): Likewise.
	* sysdeps/unix/sysv/linux/ia64/sys/ptrace.h (PTRACE_GETSIGMASK):
	Likewise.
	(PTRACE_SETSIGMASK): Likewise.
	(PTRACE_SECCOMP_GET_FILTER): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h
	(PTRACE_GETSIGMASK): Likewise.
	(PTRACE_SETSIGMASK): Likewise.
	(PTRACE_SECCOMP_GET_FILTER): Likewise.
	* sysdeps/unix/sysv/linux/s390/sys/ptrace.h (PTRACE_GETSIGMASK):
	Likewise.
	(PTRACE_SETSIGMASK): Likewise.
	(PTRACE_SECCOMP_GET_FILTER): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sys/ptrace.h (PTRACE_GETSIGMASK):
	Likewise.
	(PTRACE_SETSIGMASK): Likewise.
	(PTRACE_SECCOMP_GET_FILTER): Likewise.
	* sysdeps/unix/sysv/linux/tile/sys/ptrace.h (PTRACE_GETSIGMASK):
	Likewise.
	(PTRACE_SETSIGMASK): Likewise.
	(PTRACE_SECCOMP_GET_FILTER): Likewise.