Function compute_hir_hash 

pub fn compute_hir_hash(tcx: TyCtxt<'_>) -> Fingerprint

Compute the new, metadata-oriented HIR hash for the full crate.

Unlike the legacy hash (see legacy_crate_hash), this is an order-independent combine of each owner’s fingerprint, so it does not depend on the iteration order of the owners. It becomes part of the crate_hash which is stored in the crate metadata.