Added back a missing import.
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOM.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOM.java
index 479c5b4..d003131 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOM.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOM.java
@@ -92,6 +92,12 @@
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMNamedNode;
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMNode;
 import org.eclipse.cdt.internal.core.pdom.tag.PDOMTagIndex;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.core.runtime.OperationCanceledException;
+import org.eclipse.core.runtime.PlatformObject;
+import org.eclipse.core.runtime.Status;
 
 /**
  * Database for storing semantic information for one project.