Change CompletionLookupArranger API so that it actually works

Previously it always crashed at runtime.

platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionLookupArranger.java

@@ -17,7 +17,10 @@ public interface CompletionLookupArranger {
    * Adds an element to be arranged.
    * @param presentation The presentation of the element (rendered with {@link LookupElement#renderElement(LookupElementPresentation)}
    */
-  void addElement(LookupElement element, LookupElementPresentation presentation);
+  void addElement(LookupElement element,
+                  CompletionSorter sorter,
+                  PrefixMatcher prefixMatcher,
+                  LookupElementPresentation presentation);
 
   /**
    * Returns the items in the appropriate order and the initial selection.

platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionLookupArrangerImpl.java

@@ -136,6 +136,16 @@ public class CompletionLookupArrangerImpl extends LookupArranger implements Comp
     return true;
   }
 
+  @Override
+  public void addElement(LookupElement element,
+                         CompletionSorter sorter,
+                         PrefixMatcher prefixMatcher,
+                         LookupElementPresentation presentation) {
+    registerMatcher(element, prefixMatcher);
+    associateSorter(element, (CompletionSorterImpl)sorter);
+    addElement(element, presentation);
+  }
+
   @Override
   public void addElement(LookupElement element, LookupElementPresentation presentation) {
     StatisticsWeigher.clearBaseStatisticsInfo(element);