Deprecate or remove NDS/DDS/NDS?

[Ptival]

Those VEX specifiers no longer appear in the Intel manuals (and never appeared in AMD?), as they are subsumed by the operand encoding tables, which we also specify in <opr></opr>.

Yet we are syntactically forced to specify them in optable.xml.

I don't see anywhere where we're using them, so I'd be in favor of just dropping them entirely.

[RyanGlScott]

Yes, I agree. If we aren't using these prefixes, we shouldn't bother specifying them.