[lld] [ELF] -r --compress-debug-sections: update addends for .debug_* sections relocated by REL (PR #66804)

[Nick Desaulniers via llvm-commits]

nickdesaulniers wrote:

Forgetting compressed debug info for a minute, those LLD warnings are reproducible with:

```
$ cd linux
$ make LLVM=1 ARCH=i386 -j128 -s defconfig all
```
The warnings are not observed at the commit before your change.  Seems like a regression?

https://github.com/llvm/llvm-project/pull/66804