[Libre-soc-dev] mv.zip and mv.unzip (vector pack and unpack)

[lkcl]

https://libre-soc.org/openpower/sv/mv.swizzle/
https://libre-soc.org/openpower/sv/mv.vec

these two are driving me slightly nuts.  there are a hell of a lot of combinations to think through, and iteratively i have gone through a hell of a lot of things that just won't work.

i thought it sane/safe to add a 2nd subvector step (like srcstep/dststep) but actually (a) it is not (b) the swizzle predication bits can be used fully deterministically to *derive* one subvector step from the other.

a src_subvl separate from dst_subvl is a misnomer, they can be used to indicate pack/unpack but no more.

mv.swizzle on Scalar is insane, absolutely no chance of 8 64 bit operands, i cut it back to 2-in 2-out.

mv.vec is removed as an instruction, encoding pack/unpack in either REMAP or the new MV-RM-2P-1S1D.

moving very fast here because there are only 3.5 months left to the Oct 1st deadline.

l.