Check that function being patched has no activations on any thread stack

src/liveedit.h

Index: src/liveedit.h
diff --git a/src/liveedit.h b/src/liveedit.h
index 19caf95f144552818d20ac26374c50fa933e83e9..efbcd7404a95b9a99f4621353c3ca8aaa874b6f7 100644
--- a/src/liveedit.h
+++ b/src/liveedit.h
@@ -90,6 +90,12 @@ class LiveEdit : AllStatic {
 
   static void PatchFunctionPositions(Handle<JSArray> shared_info_array,
                                      Handle<JSArray> position_change_array);
+
+  // A copy of this is in liveedit-delay.js.
+  enum FunctionPatchabilityStatus {
+    FUNCTION_AVAILABLE_FOR_PATCH = 0,
+    FUNCTION_BLOCKED_ON_STACK = 1
+  };
 };
 
 #endif  // ENABLE_DEBUGGER_SUPPORT