Support x86-64 floating point registers.

ART uses some x86-64 floating point registers as callee save.
Therefore they are in the CFI and libunwind needs to understand them.

(cherry picked from commit d79f9bbebb13ba9f3a2676c8b8f7cd9e1a4c28d7)

Bug: 21924613
Change-Id: I57f32e5b3b795fa7d2a23e9aeb8aa72d5787a15a
2 files changed