Move ReferenceHashSet to an internal package
diff --git a/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/ReferenceHashSet.java b/bundles/org.eclipse.core.runtime/src/org/eclipse/core/internal/registry/ReferenceHashSet.java
similarity index 99%
rename from bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/ReferenceHashSet.java
rename to bundles/org.eclipse.core.runtime/src/org/eclipse/core/internal/registry/ReferenceHashSet.java
index 480c5ed..63762a0 100644
--- a/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/ReferenceHashSet.java
+++ b/bundles/org.eclipse.core.runtime/src/org/eclipse/core/internal/registry/ReferenceHashSet.java
@@ -8,7 +8,7 @@
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
-package org.eclipse.core.runtime.dynamichelpers;
+package org.eclipse.core.internal.registry;
 
 import java.lang.ref.ReferenceQueue;
 import java.lang.ref.SoftReference;
diff --git a/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/ExtensionTracker.java b/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/ExtensionTracker.java
index 1fe2327..b377e68 100644
--- a/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/ExtensionTracker.java
+++ b/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/ExtensionTracker.java
@@ -13,6 +13,7 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import org.eclipse.core.internal.registry.ReferenceHashSet;
 import org.eclipse.core.internal.runtime.ListenerList;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IExtensionDelta;
diff --git a/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/IExtensionTracker.java b/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/IExtensionTracker.java
index 10a58e3..d83e41a 100644
--- a/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/IExtensionTracker.java
+++ b/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/dynamichelpers/IExtensionTracker.java
@@ -10,6 +10,7 @@
  *******************************************************************************/
 package org.eclipse.core.runtime.dynamichelpers;
 
+import org.eclipse.core.internal.registry.ReferenceHashSet;
 import org.eclipse.core.runtime.IExtension;
 
 /**