build fix for static windows

Common/Core/SMP/Common/vtkSMPToolsImpl.h

@@ -62,7 +62,7 @@ public:
   bool GetNestedParallelism() { return this->NestedActivated; }
 
   //--------------------------------------------------------------------------------
-  bool IsParallelScope() { return this->IsParallel; }
+  bool IsParallelScope();
 
   //--------------------------------------------------------------------------------
   bool GetSingleThread();
@@ -118,6 +118,12 @@ private:
   std::atomic<bool> IsParallel{ false };
 };
 
+template <BackendType Backend>
+bool vtkSMPToolsImpl<Backend>::IsParallelScope()
+{
+  return this->IsParallel;
+}
+
 using ExecuteFunctorPtrType = void (*)(void*, vtkIdType, vtkIdType, vtkIdType);
 
 VTK_ABI_NAMESPACE_END