[llvm] [llvm-readelf] Update outdated URL (PR #120498)

[James Henderson via llvm-commits]

https://github.com/jh7370 commented:

It's worth noting that this isn't actually the latest set of registered EM_* values, just the latest set documented on the sco website. Unfortunately, they don't actively maintain/publish revisions to the ELF gABI. Instead, updates can be found on the ELF generic-abi mailing list.

Specifically, at the time of writing, I believe the latest list can be found at https://groups.google.com/g/generic-abi/c/0kORSDcyhTE/m/ZRf_PvcHAAAJ. You'll note there are a number listed there which aren't in the latest published ABI.

https://github.com/llvm/llvm-project/pull/120498