Fix source position for stack traces with optimized top function.

runtime/tests/vm/dart/optimized_stacktrace_test.dart

+// Copyright (c) 2013, 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 correct source positions in stack trace with optimized functions.
+
+// (1) Test normal exception. 
+foo(x) => bar(x);
+
+bar(x) {
+  if (x == null) throw 42;  // throw at position 11:18
+  return x + 1;
+}
+
+test1() {
+  // First unoptimized.
+  try {
+    foo(null);
+    Expect.fail("Unreachable");
+  } catch (e, stacktrace) {
+    String s = stacktrace.toString();
+    Expect.equals(-1, s.indexOf("-1:-1"));
+    Expect.notEquals(-1, s.indexOf("11:18"));
+  }
+
+  // Optimized.
+  for (var i=0; i<10000; i++) foo(42);
+  try {
+    foo(null);
+    Expect.fail("Unreachable");
+  } catch (e, stacktrace) {
+    String s = stacktrace.toString();
+    Expect.equals(-1, s.indexOf("-1:-1"));
+    Expect.notEquals(-1, s.indexOf("11:18"));
+  }
+}
+
+
+// (2) Test checked mode exceptions.
+maximus(x) => moritz(x);
+
+moritz(x) {
+  if (x == 333)  return 42 ? 0 : 1;  // Throws in checked mode.
+  if (x == 777)   {
+    bool b = x;  // Throws in checked mode.
+    return b;
+  }
+
+  return x + 1;
+}
+
+test2() {
+  for (var i=0; i<100000; i++) maximus(42);
+  try {
+    maximus(333);
+  } catch (e, stacktrace) {
+    String s = stacktrace.toString();
+    print(s);
+    Expect.notEquals(-1, s.indexOf("maximus"));
+    Expect.notEquals(-1, s.indexOf("moritz"));
+    Expect.equals(-1, s.indexOf("-1:-1"));
+  }
+
+  try {
+    maximus(777);
+  } catch (e, stacktrace) {
+    String s = stacktrace.toString();
+    print(s);
+    Expect.notEquals(-1, s.indexOf("maximus"));
+    Expect.notEquals(-1, s.indexOf("moritz"));
+    Expect.equals(-1, s.indexOf("-1:-1"));
+  }
+}
+
+main() {
+  test1();
+  test2();
+}