docs: private boolean doForwardSubstitution() {
          if (!REDUNDANT_LOAD_ELIMINATION) {
              return false;
          }
  
          XField xfield = loadedFieldSet.getField(handle);
          if (xfield == null) {
              return false;
          }
  
          if(xfield.getSignature().equals("D") || xfield.getSignature().equals("J")) {
              return false;
          }
  
          // Don't do forward substitution for fields that
          // are never read.
          return loadedFieldSet.isLoaded(xfield);
      }