Parse formal parameters.

dart/frog/tests/leg_only/src/FunctionParametersTest.dart

Index: dart/frog/tests/leg_only/src/FunctionParametersTest.dart
diff --git a/dart/frog/tests/leg_only/src/FunctionParametersTest.dart b/dart/frog/tests/leg_only/src/FunctionParametersTest.dart
new file mode 100644
index 0000000000000000000000000000000000000000..1632fb640b4409aa585c44386ebcb25a0b5e6dfb
--- /dev/null
+++ b/dart/frog/tests/leg_only/src/FunctionParametersTest.dart
@@ -0,0 +1,11 @@
+// Copyright (c) 2011, 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.
+
+void main() {
+  print(foo(3) + foo(4));
+}
+
+int foo(int a) {
+  return a;
+}