Function cross_language_comparison_id 

pub fn cross_language_comparison_id(
    origins: &[String],
) -> CrossLanguageComparisonId

Identify an explicit Rust-to-C++ semantic comparison over origin variants.

The origin list is canonicalised before hashing, while every compared graph retains its own full BuildVariant fingerprint. This identifier is only the comparison domain used to prevent unrelated requests from joining.