LLA and checkpoint/restart support for program objects

LLA (Library Lookaside) supports both the caching of PDSE program directories and the caching of program objects (loaded from PDSEs), using the same caching algorithms as for load modules. The interfaces to enable LLA are the same as they are today for load modules.
Programs can be Checkpointed and Restarted with program objects in the address space if the PDSE is not open under the user's TCB, (for example, it is OK if PDSEs are JOBLIB, STEPLIB or Linklist). In addition, there must be no overlay program objects in the address space when a Checkpoint is issued.