Add primitive to create closures and use it for closure conversion

pkg/kernel/lib/binary/ast_from_binary.dart

Index: pkg/kernel/lib/binary/ast_from_binary.dart
diff --git a/pkg/kernel/lib/binary/ast_from_binary.dart b/pkg/kernel/lib/binary/ast_from_binary.dart
index 64563eb27bd79e1f7c6b6f89ac18e8fa7c6f0ca0..caaa290f89ee66f9570de20e06891eedb5c65bba 100644
--- a/pkg/kernel/lib/binary/ast_from_binary.dart
+++ b/pkg/kernel/lib/binary/ast_from_binary.dart
@@ -828,6 +828,12 @@ class BinaryBuilder {
       case Tag.VectorCopy:
         var vectorExpression = readExpression();
         return new VectorCopy(vectorExpression);
+      case Tag.ClosureCreation:
+        var topLevelFunctionName = readStringReference();
+        var contextVector = readExpression();
+        var functionType = readDartType();
+        return new ClosureCreation(
+            topLevelFunctionName, contextVector, functionType);
       default:
         throw fail('Invalid expression tag: $tag');
     }