8026948: JvmtiEnv::SetBreakpoint and JvmtiEnv::ClearBreakpoint might not work with anonymous classes
Summary: Walk methods in breakpoints for marking on stack so they aren't deallocated by redefine classes.  Use class_holder rather than class_loader to keep GC from reclaiming class owning the method.
Reviewed-by: sspitsyn, ehelin, sla