Fix our initial dead phi elimination in the presence of try-catch.

tests/language/try_catch_optimized4_test.dart

+// Copyright (c) 2014, 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.
+// VMOptions=--optimization-counter-threshold=10
+
+import "package:expect/expect.dart";
+
+// Test correct dead phi elimination with try catch.
+
+List<Object> a = [1,2,3,4,5];
+
+class MyError { }
+
+class M {
+  maythrow(i) {
+    try {
+      if (i <= 5) throw new MyError();
+    } catch(e) { throw e; }
+  }
+}
+
+loop_test() {
+  bool failed = false;
+  M m = new M();
+  for (Object i in a) {
+    try {
+      String res = m.maythrow(i);
+      failed = true;
+    } on MyError catch(e) { }
+    if (!identical(failed, false)) {
+      Expect.fail("");
+    }
+  }
+}
+
+main() {
+  for (var i = 0; i < 20; i++) loop_test();
+}
+
+
+