[lld] [lld-macho] Fix category merging sed issue - Try nr.2 (PR #112981)

[via llvm-commits]

alx32 wrote:

> if we can get `sed` to work I'd prefer that because I think it's simpler.

Tried these, but still no go:
```
sed -E '|^__OBJC_\$_CATEGORY_MyBaseClass_\$_Category01:| { n; s|^[ \t]*\.quad[ \t]+l_OBJC_CLASS_NAME_$|\t.quad\tL_OBJC_IMAGE_INFO+3|g }' merge_cat_minimal.s > merge_cat_minimal_bad_name.s

sed -E '/^__OBJC_\$_CATEGORY_MyBaseClass_\$_Category01:/ { n; s/^[ \t]*\.quad[ \t]+l_OBJC_CLASS_NAME_$/\t.quad\tL_OBJC_IMAGE_INFO+3/; }' merge_cat_minimal.s > merge_cat_minimal_bad_name.s
```

https://github.com/llvm/llvm-project/pull/112981