These changes affect any code using the SELECT-REGISTRY-TEST

These changes affect any code using the SELECT-REGISTRY-TEST
primitive.  Runtime 14.161 requires this microcode revision or later,
but older bands can run over this microcode.

* Change interface to SELECT-REGISTRY-TEST.  Order or second and third
  arguments is reversed.  Third argument is changed from a select
  registry to a vector.  Primitive returns a nonnegative integer
  indicating the number of descriptors that were stored in the vector,
  or a negative integer indicating that nothing is stored and that
  another interesting condition holds.

* Add new primitive SELECT-DESCRIPTOR, a simplified version of
  SELECT-REGISTRY-TEST that works for a single descriptor and does not
  require consing in the interface.