DFG::operationTypeOf() needs to set the VM::topCallFrame.
<https://webkit.org/b/128228>

Reviewed by Mark Hahnenberg.

* dfg/DFGOperations.cpp:
- operationTypeOf() can end up calling into WebCore which may in turn
  call back to JSC, and need a valid VM::topCallFrame. So, we need to
  set the value of VM::topCallFrame at the top of operationTypeOf().


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@163426 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/dfg/DFGOperations.cpp b/Source/JavaScriptCore/dfg/DFGOperations.cpp
index be56c7e..fd15249 100644
--- a/Source/JavaScriptCore/dfg/DFGOperations.cpp
+++ b/Source/JavaScriptCore/dfg/DFGOperations.cpp
@@ -823,6 +823,8 @@
 
 JSCell* JIT_OPERATION operationTypeOf(ExecState* exec, JSCell* value)
 {
+    VM& vm = exec->vm();
+    NativeCallFrameTracer tracer(&vm, exec);
     return jsTypeStringForValue(exec, JSValue(value)).asCell();
 }