Check consistency of the class names and OP_ID

As the class names should be now consistent with the OP_IDs, we add a
check for wrongly-defined OP_IDs.

However, the future removal of the hand-coded OP_IDs will render this
obsolete, so this check is introduced just to make sure that the
previous renaming patches did the right job, and it will then be
removed.

The consistency checks require renaming the test opcodes, which were
using arbitrary names, depending on test author. They are now all
standardized on OpTest (local scope).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>