basic-arm-instruction tests fail on trunk

FWIW this passes with trunk now (bootstrapped with clang).

Good news, but not great news. :wink:

The MCJIT tests are notoriously noisy on ARM (maybe others, too, I don't
know), and I had to disable a whole bunch of them in the past. It may be
that they will appear again, not necessarily the same ones, though. I don't
remember the root cause of such noise (it's in this list, somewhere), but
generally a "make clean" solves most issues.