[llvm] [llvm-readobj] Dump callgraph section info for ELF (PR #157499)

[James Henderson via llvm-commits]

https://github.com/jh7370 commented:

Please make sure to update the llvm-readobj and llvm-readelf CommandGuide documents under llvm/docs.

I'm keen to review this, as I've seen several things when skimming I'd like addressed, but don't have time to review it properly this week, due to other reviews and some planned time off.

https://github.com/llvm/llvm-project/pull/157499