Types: Fix #1290: Rationalize and correct "mixed" style array dimensioning.

There a couple functional problems, which when reduced down also led to
some good simplifications and rationalization.  So, this commit:
 - corrects "mixed" functionality: int[A] f[B] -> f[B][A]
 - correct multi-identifier decls: int[A] f[B], g[C] -> f and g are independently sized.
 - increases symmetry between different places in the code that do this
 - makes fewer ways to do the same thing; several methods are just gone now
 - makes more clear when something is copied or shared