Removes unused 'normalized' field in many AST nodes.

compiler/java/com/google/dart/compiler/ast/DartIdentifier.java

Index: compiler/java/com/google/dart/compiler/ast/DartIdentifier.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartIdentifier.java b/compiler/java/com/google/dart/compiler/ast/DartIdentifier.java
index a512779a70bccc4eb82c840116605638d145cd33..131a67def799bab74f8f1e944e6ddc97a429862c 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartIdentifier.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartIdentifier.java
@@ -14,7 +14,6 @@ public class DartIdentifier extends DartExpression implements ElementReference {
 
   private final String targetName;
   private Element targetSymbol;
-  private DartExpression normalizedNode = this;
   private Element referencedElement;
 
   public DartIdentifier(String targetName) {
@@ -26,16 +25,6 @@ public class DartIdentifier extends DartExpression implements ElementReference {
     this.targetName = original.targetName;
   }
 
-  public void setNormalizedNode(DartExpression normalizedNode) {
-    normalizedNode.setSourceInfo(this);
-    this.normalizedNode = normalizedNode;
-  }
-
-  @Override
-  public DartExpression getNormalizedNode() {
-    return normalizedNode;
-  }
-
   @Override
   public Element getSymbol() {
     return targetSymbol;