[lld] [lld-macho] Fix invalid DWARF with --icf=safe_thunks (PR #111097)

[Kyungwoo Lee via llvm-commits]

================
@@ -1229,6 +1229,17 @@ void SymtabSection::emitStabs() {
       if (defined->isAbsolute())
         continue;
 
+      // Never generate a STABS entry for a symbol that has been ICF'ed using a
+      // thunk - just like we do for fully ICF'ed functions. Otherwise we end up
+      // generating invalid DWARF as dsymutil will think the entire function
----------------
kyulee-com wrote:

```suggestion
      // generating invalid DWARF as dsymutil will assume the entire function
```

https://github.com/llvm/llvm-project/pull/111097