1) Test funky addressing modes.
2) Test abs.w addressing mode.  We don't test it now because we don't
   know that the pointer to the test data will fit in two bytes (in fact,
   it won't).
3) Check undefined behavior for mull when dh and di are the same register.
4) unlk a7 wedges the 68040, so we aren't testing it.  When we run the test
   suite on a 68020, we may want to put it back in.
5) Test move16