8238358: Implementation of JEP 371: Hidden Classes

Co-authored-by: Lois Foltan <lois.foltan@oracle.com>
Co-authored-by: David Holmes <david.holmes@oracle.com>
Co-authored-by: Harold Seigel <harold.seigel@oracle.com>
Co-authored-by: Serguei Spitsyn <serguei.spitsyn@oracle.com>
Co-authored-by: Alex Buckley <alex.buckley@oracle.com>
Co-authored-by: Jamsheed Mohammed C M <jamsheed.c.m@oracle.com>
Co-authored-by: Jan Lahoda <jan.lahoda@oracle.com>
Co-authored-by: Amy Lu <amy.lu@oracle.com>
Reviewed-by: alanb, cjplummer, coleenp, dholmes, dlong, forax, jlahoda, psandoz, plevart, sspitsyn, vromero