[debug] fix exception prediction for asm frames.

test/mjsunit/regress/regress-crbug-633999.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax --noturbo
+
+var Debug = debug.Debug
+var exception = null;
+var step = 0;
+
+function listener(event, exec_state, event_data, data) {
+  if (event != Debug.DebugEvent.Exception) return;
+  try {
+    step++;
+  } catch (e) {
+    exception = e;
+  }
+}
+
+Debug.setBreakOnException();
+Debug.setListener(listener);
+
+(function () {
+  "use asm";
+  function f() {
+    try {
+      throw 666;
+    } catch (e) {
+    }
+  }
+  f();
+  f();
+  %OptimizeFunctionOnNextCall(f);
+  f();
+  assertOptimized(f);
+})();
+
+Debug.setListener(null);
+assertNull(exception);
+assertEquals(3, step);