[lld] [lld-macho] Implement ObjC category merging (-objc_category_merging) (PR #82928)

[via llvm-commits]

================
@@ -203,6 +205,8 @@ void macho::writeMapFile() {
     for (const OutputSection *osec : seg->getSections()) {
       if (auto *concatOsec = dyn_cast<ConcatOutputSection>(osec)) {
         for (const InputSection *isec : concatOsec->inputs) {
+          if (isec->isLinkOptimizedAway())
+            continue;
----------------
alx32 wrote:

Will switch to just using 'live'. 

https://github.com/llvm/llvm-project/pull/82928