Throw and a small fix to If.

frog/tests/leg_only/src/Throw2Test.dart

+// 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 throw1() {
+  throw "foo";
+}
+
+void throw2() {
+  if (true) throw "foo";
+}
+
+void throw3() {
+  if (false) {
+    print("argh");
+  } else {
+    throw "foo";
+  }
+}
+
+void throw4() {
+  if (true) {
+    throw "foo";
+  } else {
+    throw "bar";
+  }
+}
+
+void nonThrow5() {
+  if (false) throw "foo";
+}
+
+void main() {
+  throw1();  /// 01: runtime error
+  throw2();  /// 02: runtime error
+  throw3();  /// 03: runtime error
+  throw4();  /// 04: runtime error
+  nonThrow5();
+}