added emulator support for arm.
added emulator support for arm.

R=rsc
APPROVED=rsc
DELTA=7  (3 added, 0 deleted, 4 changed)
OCL=34661
CL=34820
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go