Add %GetCallerJSFunction intrinsic

test/mjsunit/get-caller-js-function-throws.js

Index: test/mjsunit/get-caller-js-function-throws.js
diff --git a/test/mjsunit/get-caller-js-function-throws.js b/test/mjsunit/get-caller-js-function-throws.js
new file mode 100644
index 0000000000000000000000000000000000000000..42b098aee9e0f85c31eabba0abc4ab33fbdbe065
--- /dev/null
+++ b/test/mjsunit/get-caller-js-function-throws.js
@@ -0,0 +1,14 @@
+// Copyright 2015 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: --allow-natives-syntax --noalways-opt --nostress-opt
+
+// Ensure that "real" js functions that call GetCallerJSFunction get an
+// exception, since they are not stubs.
+(function() {
+  var a = function() {
+    return %_GetCallerJSFunction();
+  }
+  assertThrows(a);
+}());