Fix compilation errors in VS due to template declaration

[feast107]

This causes various continuous lines of compilation error within vs.

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[googleberg]

@feast107 Please sign the CLA so we can assign a reviewer to this PR. For more information see: https://github.com/protocolbuffers/protobuf/pull/11034/checks?check_run_id=9617744316

[feast107]

@feast107 Please sign the CLA so we can assign a reviewer to this PR. For more information see: https://github.com/protocolbuffers/protobuf/pull/11034/checks?check_run_id=9617744316

Thanks for your reminding, I've now signed the CLA.

[feast107]

I would like to know the build situation this time

[googleberg]

@feast107 I think you'll need to rebase this PR to get past a testing breakage.

[deannagarcia]

@feast107 If you rebase this PR I can rerun the tests for you!

[haberman]

btw, you will want to rebase on our main branch, there have been a lot of changes in our testing infrastructure in the last few weeks.