Add a virtual class for BuildInfo entries.
Add a virtual class for BuildInfo entries.

PiperOrigin-RevId: 446445268

bazelbuild/bazel,cushon/bazel,katre/bazel,katre/bazel,cushon/bazel,katre/bazel,cushon/bazel,bazelbuild/bazel,katre/bazel,katre/bazel,bazelbuild/bazel,bazelbuild/bazel,katre/bazel,cushon/bazel,bazelbuild/bazel,bazelbuild/bazel,cushon/bazel,cushon/bazel