Bin2llvmir: application of similar versions of statically linked code signatures

If we detect compiler version, but we do not have statically linked code signatures for this exact version, we could try to apply signatures of closely similar version - if we have them.

Try:
1. Try to experiment with it and find out, if it makes sense - similar versions have significant overlap.
2. If so, implement an intelligent algorithm of signature application - applies close versions, but not totally different ones.

Start by locating the Bin2llvmir entry point that detects compiler versions and applies statically linked code signatures. Experiment with the overlap between signatures from nearby versions, then define how similarity should be measured and when a version is too different. Done means a tested selection algorithm applies suitable close-version signatures without using unrelated ones.

Written by the indexing model from the issue text.