[clang] [llvm] [PowerPC] Tune AIX shared library TLS model at function level by heuristic (PR #84132)

[Amy Kwan via cfe-commits]

================
@@ -848,6 +848,14 @@ void PPCAsmPrinter::emitInstruction(const MachineInstr *MI) {
         return MCSymbolRefExpr::VariantKind::VK_PPC_AIX_TLSLE;
       if (Model == TLSModel::InitialExec)
         return MCSymbolRefExpr::VariantKind::VK_PPC_AIX_TLSIE;
+      // On AIX, TLS model heuristic may have turned local-dynamic access into
+      // initial-exec access.
----------------
amy-kwan wrote:

```suggestion
      // On AIX, TLS model heuristics may have turned local-dynamic accesses into
      // initial-exec accesses.
```

https://github.com/llvm/llvm-project/pull/84132