Check for compile-time constants in DartCompiler

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

Index: compiler/java/com/google/dart/compiler/ast/DartExpression.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartExpression.java b/compiler/java/com/google/dart/compiler/ast/DartExpression.java
index 9b0bb15a81cf9144ed77f6e9c1bb0e536950dacd..5a784ebb8bc702e57da52478b862b0b478827607 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartExpression.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartExpression.java
@@ -4,10 +4,13 @@
 
 package com.google.dart.compiler.ast;
 
+import com.google.dart.compiler.type.Type;
+
 /**
  * Abstract base class for Dart expressions.
  */
 public abstract class DartExpression extends DartNode {
+  Type type;
 
   public boolean isAssignable() {
     // By default you cannot assign to expressions.
@@ -18,4 +21,14 @@ public abstract class DartExpression extends DartNode {
   public DartExpression getNormalizedNode() {
     return (DartExpression) super.getNormalizedNode();
   }
+
+  @Override
+  public void setType(Type type) {
+   this.type = type;
+  }
+
+  @Override
+  public Type getType() {
+    return type;
+  }
 }