[clang] Reland: [clang] Track function template instantiation from definition (PR #125266)

[via cfe-commits]

llvmbot wrote:

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Failed to cherry-pick: 346077aaa6bef5652a72a2f3d9fc134ea8fc6a5b

https://github.com/llvm/llvm-project/actions/runs/13209645800

Please manually backport the fix and push it to your github fork.  Once this is done, please create a [pull request](https://github.com/llvm/llvm-project/compare)

https://github.com/llvm/llvm-project/pull/125266