Fix several bugs in closure conversion.

pkg/kernel/testcases/closures/arity.dart

Index: pkg/kernel/testcases/closures/arity.dart
diff --git a/pkg/kernel/testcases/closures/arity.dart b/pkg/kernel/testcases/closures/arity.dart
new file mode 100644
index 0000000000000000000000000000000000000000..ed13ee6872a7f9b9e1f773c852ef7d596d373bf0
--- /dev/null
+++ b/pkg/kernel/testcases/closures/arity.dart
@@ -0,0 +1,22 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+main() {
+  var closures = [
+    (x, y, [z]) {},
+    (x, y, z) {},
+    (x, y, {z}) {},
+    (x, y, z, w, v) {}
+  ];
+  for (var c in closures) {
+    bool ok = false;
+    try {
+      c(1, 2, 3, 4);
+    } on NoSuchMethodError catch (_) {
+      ok = true;
+    }
+    if (!ok) {
+      throw new Exception("Expected an error!");
+    }
+  }
+}