Issue 5042. Fix for resolving [], []= and [] op=

compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java

Index: compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
diff --git a/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java b/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
index 791eb2f6984cd4dc58f6244a4226750d50992ef8..3dfe02970a9e9608f120535f2b7c42e26487bd86 100644
--- a/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
+++ b/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
@@ -1360,7 +1360,7 @@ public class TypeAnalyzer implements DartCompilationPhase {
       if (node.getParent() instanceof DartBinaryExpression) {
         DartBinaryExpression binaryExpression = (DartBinaryExpression) node.getParent();
         if (binaryExpression.getArg1() == node
-            && binaryExpression.getOperator().isAssignmentOperator()) {
+            && binaryExpression.getOperator() == Token.ASSIGN) {
           DartExpression argValue = binaryExpression.getArg2();
           analyzeTernaryOperator(node, target, Token.ASSIGN_INDEX, node, argKey, argValue);
           binaryExpression.setElement(node.getElement());