[llvm] [PowerPC] Alignment of toc-data symbol should not be increased during optimizations (PR #94593)

[Eli Friedman via llvm-commits]

================
@@ -335,6 +335,15 @@ bool GlobalObject::canIncreaseAlignment() const {
   if (isELF && !isDSOLocal())
     return false;
 
+  // GV with toc-data attribute is defined in a TOC entry. To mitigate TOC
+  // overflow, the alignment of such symbol should not be increased. Otherwise,
+  // padding is needed thus more TOC entries are wasted.
+  bool isXCOFF =
+      (!Parent || Triple(Parent->getTargetTriple()).isOSBinFormatXCOFF());
+  if (isXCOFF)
+    if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(this))
+      return !GV->hasAttribute("toc-data");
----------------
efriedma-quic wrote:

```suggestion
      if (GV->hasAttribute("toc-data"))
        return false;
```

https://github.com/llvm/llvm-project/pull/94593