Add missing arm64 registers.

Also fix dumping of arm64's vector registers, which are actually 128 bits wide.

Also move the arm/arm64 FP registers to the tombstone. (We've never dumped
them at all for the other architectures.)

(cherry picked from commit b40c5035)

Change-Id: Ic646fb9ea01e9beb42e1757feb8742c1d4efafa7