faster SLOT-VALUE &co with variable slot names

faster SLOT-VALUE &co with variable slot names

* Cache the slot-location and typecheckfun in the class-slots-vector
  in addition to the slot-definition for STANDARD-CLASS and
  FUNCALLABLE-STANDARD-CLASS.

* New function CHECK-OBSOLETE-INSTANCE/CLASS-OF, which combines the
  two. Faster then calling both separately, since both need to grab
  the wrapper -- used by SLOT-VALUE &co.

* Unoptimized SLOT-VALUE, (SETF SLOT-VALUE), SLOT-BOUNDP, and
  SLOT-MAKUNBOUND can now directly access instance and class slots the
  typecheckfun in normal cases, giving upto 20-25% performance boost
  for these functions.

* Obsolete-instance protocol tests using variable slot-names.