Externalize deoptimization reasons.

test/mjsunit/assert-opt-and-deopt.js

Index: test/mjsunit/assert-opt-and-deopt.js
diff --git a/test/mjsunit/assert-opt-and-deopt.js b/test/mjsunit/assert-opt-and-deopt.js
index e9aba1d3c92d0f7a4ecf47df08f091fc210fe7a4..0a2f95d8725845c20d0d58bc82bde21080053871 100644
--- a/test/mjsunit/assert-opt-and-deopt.js
+++ b/test/mjsunit/assert-opt-and-deopt.js
@@ -181,3 +181,37 @@ tracker.AssertOptCount(f, 2);
 tracker.AssertIsOptimized(f, true);
 tracker.AssertDeoptHappened(f, true);
 tracker.AssertDeoptCount(f, 1);
+
+
+function deoptTest() {
+  function k(a) {
+    return a / 10;
+  }
+
+  function f(a) {
+    return k(a);
+  }
+
+  var tracker = new OptTracker();
+  tracker.CheckpointOptCount(f);
+
+  f(10);
+  %OptimizeFunctionOnNextCall(f);
+  f(10);
+
+  tracker.AssertOptCount(f, 1);
+  tracker.AssertIsOptimized(f, true);
+  tracker.AssertDeoptHappened(f, false);
+  tracker.AssertDeoptCount(f, 0);
+
+  try {
+    f('a');
+  } catch(e) {
+  }
+
+  tracker.AssertIsOptimized(f, false);
+  tracker.AssertDeoptHappened(f, true);
+  tracker.AssertDeoptCount(f, 1);
+}
+
+deoptTest();