intel/fs: general 8/16/32/64-bit shuffle_src_to_dst function

intel/fs: general 8/16/32/64-bit shuffle_src_to_dst function

This new function takes care of shuffle/unshuffle components of a
particular bit-size in components with a different bit-size.

If source type size is smaller than destination type size the operation
needed is a component shuffle. The opposite case would be an unshuffle.

Component units are measured in terms of the smaller type between
source and destination. As we are un/shuffling the smaller components
from/into a bigger one.

The operation allows to skip first_component number of components from
the source.

Shuffle MOVs are retyped using integer types avoiding problems with
denorms and float types if source and destination bitsize is different.
This allows to simplify uses of shuffle functions that are dealing with
these retypes individually.

Now there is a new restriction so source and destination can not overlap
anymore when calling this shuffle function. Following patches that migrate
to use this new function will take care individually of avoiding source
and destination overlaps.

v2: (Jason Ekstrand)
    - Rewrite overlap asserts.
    - Manage type_sz(src.type) == type_sz(dst.type) case using MOVs
      from source to dest. This works for 64-bit to 64-bits
      operation that on Gen7 as it doesn't support Q registers.
    - Explain that components units are based in the smallest type.
v3: - Fix unshuffle overlap assert (Jason Ekstrand)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>