7092412: G1: Some roots not marked during an initial mark that gets an evacuation failure Summary: As a result of the changes for 7080389, an evacuation failure during an initial mark pause may result in some root objects not being marked. Pass whether the caller is a root scanning closure into the evacuation failure handling code so that the thread that successfully forwards an object to itself also marks the object. Reviewed-by: ysr, brutisso, tonyp