Comment by ignoramous

> Symbols would be resolved based on an index where only updated object files are reindexed. It could also eagerly relocate in the background, in order depending on previous usage data.

Not exactly this, but Google's Propeller fixes up ("relinks") Basic Blocks (hot code as traced from PGO) in native code at runtime (like an optimizing JIT compiler would): https://research.google/pubs/propeller-a-profile-guided-reli...