This allows overriding libfiles.txt to not include ListSpecs and proof package, allowing for ~2.0s gain in startup time (5.5s vs 7.5s on a simple example).
Allow for libfiles.txt to be empty (i.e. no Stainless library)
Startup time can be reduced to ~1.2s on a simple example.
ListOpsandListSpecsinto their own fileslibfiles.txtto not includeListSpecsandproofpackage, allowing for ~2.0s gain in startup time (5.5s vs 7.5s on a simple example).libfiles.txtto be empty (i.e. no Stainless library)