Move the workaround for latest VS2019 from rootcling_impl.cxx to CIFactory.cpp
Move the workaround for latest VS2019 from rootcling_impl.cxx to CIFactory.cpp

Following the discussion [on GitHub](https://github.com/root-project/cling/commit/df0e84968ab9fe7ea280b4ae78203675f68438f5#), move back the workaround for Visual Studio 2019 v16.7.0 from `rootcling_impl.cxx` to `CIFactory.cpp`

root-mirror/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling