1.0.28.47: depessimize accesses to maybe non-simple arrays with known element types

1.0.28.47: depessimize accesses to maybe non-simple arrays with known element types

  The transforms for HAIRY-DATA-VECTOR-(REF|SET) which inserted a call
  to %DATA-VECTOR-AND-INDEX were never a win unless the array was
  known to be simple: the element type dispatch is quite effcient, and
  the slow path has an open coded WITH-ARRAY-DATA which performs
  better.

  For simple arrays the transforms remain a win, since
  %DATA-VECTOR-AND-INDEX will be open coded: at most one dereference
  is ever necessary.

  Unfortunately declaring the element type of a non-simple array remains
  a loss -- just a less drastic one then before.