7039089: G1: changeset for 7037276 broke heap verification, and related cleanups Summary: In G1 heap verification, we no longer scan perm to G1-collected heap refs as part of process_strong_roots() but rather in a separate explicit oop iteration over the perm gen. This preserves the original perm card-marks. Added a new assertion in younger_refs_iterate() to catch a simple subcase where the user may have forgotten a prior save_marks() call, as happened in the case of G1's attempt to iterate perm to G1 refs when verifying the heap before exit. The assert was deliberately weakened for ParNew+CMS and will be fixed for that combination in a future CR. Also made some (non-G1) cleanups related to code and comments obsoleted by the migration of Symbols to the native heap. Reviewed-by: iveresov, jmasa, tonyp

// A simple class to extend an abstract class and get loaded with different
// loaders.  This class is loaded via LOADER2.
public class from_loader2 implements IFace {
  public many_loader[] gen() {
    many_loader[] x = new many_loader[1];
    x[0] = new many_loader();
    return x;
  }
}