Issue 4090. For-in loop variable should not be visible in iterable expression.

compiler/java/com/google/dart/compiler/resolver/Resolver.java

Index: compiler/java/com/google/dart/compiler/resolver/Resolver.java
diff --git a/compiler/java/com/google/dart/compiler/resolver/Resolver.java b/compiler/java/com/google/dart/compiler/resolver/Resolver.java
index c0dce421c65c989f9a2d3444f2deec9293ab2b65..674fdc199488ede76e933039851c25bff57b1a56 100644
--- a/compiler/java/com/google/dart/compiler/resolver/Resolver.java
+++ b/compiler/java/com/google/dart/compiler/resolver/Resolver.java
@@ -910,12 +910,12 @@ public class Resolver {
       getContext().pushScope("<for in>");
       addLabelToStatement(x);
 
+      x.getIterable().accept(this);
       if (x.introducesVariable()) {
         resolveVariableStatement(x.getVariableStatement(), true);
       } else {
         x.getIdentifier().accept(this);
       }
-      x.getIterable().accept(this);
       x.getBody().accept(this);
       getContext().popScope();
       return null;