implement kernel -> ssa for function that returns a constant

tests/compiler/dart2js/kernel/simple_function_test.dart

Index: tests/compiler/dart2js/kernel/simple_function_test.dart
diff --git a/tests/compiler/dart2js/kernel/simple_function_test.dart b/tests/compiler/dart2js/kernel/simple_function_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..9daf5e3e37049d72369de07b9e6294df8ff6b002
--- /dev/null
+++ b/tests/compiler/dart2js/kernel/simple_function_test.dart
@@ -0,0 +1,9 @@
+import 'package:test/test.dart';
+
+import 'helper.dart' show check;
+
+main() {
+  test('compile function that returns a constant', () {
+    return check("main() { return 1; }");
+  });
+}