[debugger] add mixed-stack tests.

test/mjsunit/ignition/debug-step-mixed-stack.js

Index: test/mjsunit/ignition/debug-step-mixed-stack.js
diff --git a/test/mjsunit/ignition/debug-step-mixed-stack.js b/test/mjsunit/ignition/debug-step-mixed-stack.js
new file mode 100644
index 0000000000000000000000000000000000000000..6566431175dd01396fd7b14cfb490f6c5b03ebd2
--- /dev/null
+++ b/test/mjsunit/ignition/debug-step-mixed-stack.js
@@ -0,0 +1,53 @@
+// 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
+
+Debug = debug.Debug
+
+var exception = null;
+var frame_depth = 11;
+
+function listener(event, exec_state, event_data, data) {
+  if (event != Debug.DebugEvent.Break) return;
+  try {
+    assertEquals(frame_depth, exec_state.frameCount());
+    assertTrue(/\/\/ Break$/.test(exec_state.frame(0).sourceLineText()));
+    assertEquals(12 - frame_depth, exec_state.frame(0).evaluate("x").value());
+    if (frame_depth > 2) exec_state.prepareStep(Debug.StepAction.StepOut);
+    frame_depth--;
+  } catch (e) {
+    exception = e;
+    print(e + e.stack);
+  }
+}
+
+function ChooseCode(f, x) {
+  switch (x % 2) {
+    case 0:
+      %BaselineFunctionOnNextCall(f);
+      break;
+    case 1:
+      %InterpretFunctionOnNextCall(f);
+      break;
+  }
+}
+
+function factorial(x) {
+  ChooseCode(factorial, x);
+  if (x == 1) {
+    debugger;         // Break
+    return 1;
+  }
+  var factor = factorial(x - 1);
+  return x * factor;  // Break
+}
+
+Debug.setListener(listener);
+
+assertEquals(3628800, factorial(10));
+
+Debug.setListener(null);
+assertNull(exception);
+assertEquals(1, frame_depth);