[Interpreter] Fix GenerateSmiToDouble to avoid assuming it is called from a JSFrame.

test/mjsunit/ignition/regress-612386-smi-to-double-transition.js

Index: test/mjsunit/ignition/regress-612386-smi-to-double-transition.js
diff --git a/test/mjsunit/ignition/regress-612386-smi-to-double-transition.js b/test/mjsunit/ignition/regress-612386-smi-to-double-transition.js
new file mode 100644
index 0000000000000000000000000000000000000000..275f7d62d33394a20acbe2dda65ed7defb539d6a
--- /dev/null
+++ b/test/mjsunit/ignition/regress-612386-smi-to-double-transition.js
@@ -0,0 +1,29 @@
+// 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: --no-inline-new
+
+function keyed_store(obj, key, value) {
+  obj[key] = value;
+}
+
+function foo() {
+  obj = {};
+  obj.smi = 1;
+  obj.dbl = 1.5;
+  obj.obj = {a:1};
+
+  // Transition keyed store IC to polymorphic.
+  keyed_store(obj, "smi", 100);
+  keyed_store(obj, "dbl", 100);
+  keyed_store(obj, "obj", 100);
+
+  // Now call with a FAST_SMI_ELEMENTS object.
+  var smi_array = [5, 1, 1];
+  keyed_store(smi_array, 1, 6);
+  // Transition from FAST_SMI_ELEMENTS to FAST_DOUBLE_ELEMENTS.
+  keyed_store(smi_array, 2, 1.2);
+}
+
+foo();