[llvm] [AIX] Support per global code model. (PR #79202)

[Amy Kwan via llvm-commits]

================
@@ -2680,21 +2680,34 @@ MCSection *TargetLoweringObjectFileXCOFF::getSectionForFunctionDescriptor(
 
 MCSection *TargetLoweringObjectFileXCOFF::getSectionForTOCEntry(
     const MCSymbol *Sym, const TargetMachine &TM) const {
-  // Use TE storage-mapping class when large code model is enabled so that
-  // the chance of needing -bbigtoc is decreased. Also, the toc-entry for
-  // EH info is never referenced directly using instructions so it can be
-  // allocated with TE storage-mapping class.
-  // The "_$TLSML" symbol for TLS local-dynamic mode requires XMC_TC, otherwise
-  // the AIX assembler will complain.
+  const XCOFF::StorageMappingClass SMC = [](const MCSymbol *Sym,
+                                            const TargetMachine &TM) {
+    const MCSymbolXCOFF *XSym = cast<MCSymbolXCOFF>(Sym);
+
+    // The "_$TLSML" symbol for TLS local-dynamic mode requires XMC_TC,
+    // otherwise the AIX assembler will complain.
+    if (XSym->getSymbolTableName() == "_$TLSML")
+      return XCOFF::XMC_TC;
+
+    // Use large code model toc entries for ehinfo symbols as they are
+    // never refrenced directly. The runtime loads their TOC entry
----------------
amy-kwan wrote:

```suggestion
    // never referenced directly. The runtime loads their TOC entry
```

https://github.com/llvm/llvm-project/pull/79202