Fix lazy deoptimization in the presence of exceptions

tests/language/vm/lazy_deopt_with_exception_test.dart

+// Copyright (c) 2016, 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.
+// Test deoptimization on an optimistically hoisted smi check.
+// VMOptions=--optimization-counter-threshold=10  --no-background-compilation --enable-inlining-annotations
+
+// Test that lazy deoptimization works if the program returns to a function
+// that is scheduled for lazy deoptimization via an exception.
+
+import 'package:expect/expect.dart';
+
+class C {
+  var x = 42;
+}
+
+
+const NeverInline = "NeverInline";
+
+@NeverInline
+AA(C c, bool b) {
+  if (b) {
+    c.x = 2.5;
+    throw 123;
+  }
+}
+
+@NeverInline
+T1(C c, bool b) {
+  try {
+    AA(c, b);
+  } on dynamic {
+  }
+  return c.x + 1;
+}
+
+
+@NeverInline
+T2(C c, bool b) {
+  try {
+    AA(c, b);
+  } on String {
+    Expect.isTrue(false);
+  } on int catch(e) {
+    Expect.equals(e, 123);
+    Expect.equals(b, true);
+    Expect.equals(c.x, 2.5);
+  }
+  return c.x + 1;
+}
+
+
+main() {
+  var c = new C();
+  for (var i = 0; i < 10000; ++i) {
+    T1(c, false);
+    T2(c, false);
+  }
+  Expect.equals(43, T1(c, false));
+  Expect.equals(43, T2(c, false));
+  Expect.equals(3.5, T1(c, true));
+  Expect.equals(3.5, T2(c, true));
+}
+
+