Fix bug with optimized try-catch and unboxed values.

tests/language/try_catch_optimized3_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 --no-use-osr
+
+import "package:expect/expect.dart";
+
+// Test unboxed double operations inside try-catch.
+foo(bool b) {
+  if (b) throw 123;
+}
+
+test_double(double x, bool b) {
+  try {
+    x += 1.0;
+    foo(b);
+  } catch (e) {
+    var result = x - 1.0;
+    Expect.equals(1.0, result);
+    return result;
+  }
+}
+
+main() {
+  for (var i=0; i<100; i++) test_double(1.0, false);
+  test_double(1.0, false);
+  Expect.equals(1.0, test_double(1.0, true));
+}
+