Patch [1/4] async-signal safe TLS.

2013-12-18  Andrew Hunter  <ahh@google.com>

	* sysdeps/generic/ldsodefs.h (_dl_mask_all_signals): New prototype.
	(_dl_unmask_signals): Likewise.
	* sysdeps/mach/hurd/dl-sysdep.h (_dl_mask_all_signals): New stub.
	(_dl_unmask_all_signals): Likewise.
	* sysdeps/unix/sysv/linux/dl-sysdep.h (_dl_mask_all_signals): New prototype.
	(_dl_unmask_all_signals): Likewise.
	* sysdeps/unix/sysv/linux/dl-sysdep.c (_dl_mask_all_signals): New function.
	(_dl_unmask_signals): Likewise.