[FEATURE] Add a relocation option for definition differences

[1superchip]

In some cases, the target object has global variables externed while the base object has them defined. This leads to a diff for the variables. It would be great if there was an option to ignore this difference.

The example is from objdiff on decomp.me but this applies to objdiff locally too.

https://decomp.me/scratch/xqV79

Target:

Base:

[ifarbod]

My current workflow has all global and static vars marked as extern, I only have functions inside my .obj files. This would be a nice to have feature.

Upon a shallow inspection in the code (https://github.com/encounter/objdiff/blob/main/objdiff-core%2Fsrc%2Fdiff%2Fmod.rs), I noticed Section-less vars are marked as extern, although I can't figure out how to add a new config var myself, maybe I'll give it another look soon.

[encounter]

Unless I'm misunderstanding, this already exists by setting "Function Relocation Diffs" -> "None".

(Separately, the objdiff/decomp.me embed doesn't properly persist settings, which will be fixed.)

[ifarbod]

@encounter Disabling relocation diffs altogether is undesirable, we only want to ignore variables' extern-ness.

[ifarbod]

@1superchip Can you check the latest CI build to see if it's fixed on your end? for me, it's still not