[clang] [Clang][ssaf] Add missing instantiations of `Registry<JSONFormat::FormatInfo>` (PR #181806)

[Balázs Benics via cfe-commits]

steakhal wrote:

Thanks for the prompt fix btw. It would have taken me to figure out that this is again this registry thing that I broke.

https://github.com/llvm/llvm-project/pull/181806