Fix many bugs with closure conversion in checked mode.

pkg/kernel/testcases/closures/closure_types.dart

Index: pkg/kernel/testcases/closures/closure_types.dart
diff --git a/pkg/kernel/testcases/closures/closure_types.dart b/pkg/kernel/testcases/closures/closure_types.dart
new file mode 100644
index 0000000000000000000000000000000000000000..c854593929f3d3de9b331ce0b30a54538bdb485e
--- /dev/null
+++ b/pkg/kernel/testcases/closures/closure_types.dart
@@ -0,0 +1,48 @@
+class C<T> {

[Dmitry Stefantsov, 2017/08/28 11:38:15]

Please add a standard preamble and a description.

[sjindel, 2017/08/28 15:05:59]

Done.

+  void getf() {
+    T fn(T x) {
+      return x;
+    }
+
+    ;
+    return fn;
+  }
+}
+
+typedef void ct(int x);
+
+void test_c() {
+  var x = new C<int>().getf();
+  assert(x is ct);
+
+  var y = new C<String>().getf();
+  assert(y is! ct);
+}
+
+class D<T> {
+  void getf<S>() {
+    T fn(S y) {
+      return null;
+    }
+
+    return fn;
+  }
+}
+
+typedef String dt(int x);
+
+void test_d() {
+  var x = new D<String>().getf<int>();
+  assert(x is dt);
+
+  var y = new D<int>().getf<int>();
+  assert(y is! dt);
+
+  var z = new D<int>().getf<String>();
+  assert(z is! dt);
+}
+
+main() {
+  test_c();
+  test_d();
+}