Making various changes to ALLRM incompatible to subclasses, so be explicit...

Making various changes to ALLRM incompatible to subclasses, so be explicit that this is distinct from RunMap only for purposes of clarity and testing.

core/src/main/java/jenkins/model/lazy/AbstractLazyLoadRunMap.java

@@ -140,6 +140,7 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer,R> i
      */
     private File dir;
 
+    @Restricted(NoExternalUse.class) // subclassing other than by RunMap does not guarantee compatibility
     protected AbstractLazyLoadRunMap(File dir) {
         initBaseDir(dir);
     }