This patch fixes several failures in virtfunc.exp for arm-sim/-mthumb. The
problem is that the non-virtual thunk for pDe->vg() is emitted in ARM mode
and called via _call_via_r2. But the rest of the program is Thumb mode, and
nothing tells the simulator (or target; I haven't tested this on hardware
yet but I expect the same result) to switch to ARM. So it gets very
confused.
This is somewhat suboptimal in that if you want, for some reason, to call
something marked as an ARM function with Thumb mode enabled you will have to
set $ps yourself _after_ setting $pc. I think it's still a good idea,
though. OK?