1.0.42.37: use more NAMED-LAMBDAs in PCL generated code

 Previously backtraces and profiles showed eg.

   (LAMBDA (.ARG0. .ARG1. .ARG2.))

 for effective method functions, and

   (LAMBDA (VALUE))

 for slot typechecking functions.

 Use NAMED-LAMBDA to name these sensibly:

  (DFUN <generic-function-name>)

  (SLOT-TYPECHECK <class-name> <slot-name>)