8079408: Reimplement TraceClassLoading, TraceClassUnloading, and TraceClassLoaderData with Unified Logging.
Summary: TraceClassLoading, TraceClassUnloading, and TraceClassLoaderData have been reimplemented using Unified logging.
Reviewed-by: iklam, coleenp, dholmes, jiangli, hseigel, rprotacio
Contributed-by: max.ockner@oracle.com, ioi.lam@oracle.com