Introduce a way to execute a callback on threads without performing a global VM safepoint. Make it both possible and cheap to stop individual threads and not just all threads or none.
Co-authored-by: Mikael Gerdin <mikael.gerdin@oracle.com>
Co-authored-by: Erik Osterlund <erik.osterlund@oracle.com>
Reviewed-by: mdoerr, neliasso, acorn, aph, coleenp, dholmes
