Yet again, try to fix vec4 calculation of n-dimensional array index.
vec4 versions of %cassign/vec4/off and %force/vec4/off send flags[4].
Fix vec4 overflow of times when they are >32bits.
Fix system function call in net types to get proper vector width.

This means using some of the new vec4 infrastructure to get at the
data, instead of using the old thread bit pointers. In the process,
remove the vbit and vwid members that pointed to thread bits. Those
bits no longer exist.