ARM: Allow building __longjmp as Thumb.

Convert __longjmp code to allow building as Thumb.

ports/ChangeLog.arm:

2013-10-04  Will Newton  <will.newton@linaro.org>

	* sysdeps/arm/__longjmp.S (NO_THUMB): Remove define.
	(__longjmp): Use Thumb supported instructions.
	* sysdeps/unix/sysv/linux/arm/____longjmp_chk.S (NO_THUMB):
	Remove define.
ARM: Allow building __sigsetjmp as Thumb.

Convert __sigsetjmp code to allow building as Thumb.

ports/ChangeLog.arm:

2013-10-04  Will Newton  <will.newton@linaro.org>

	* sysdeps/arm/setjmp.S (NO_THUMB): Remove define.
	(__sigsetjmp): Use Thumb supported instructions.