[clang] [Sparc][clang] Match GCC's SPARC V8 vector return convention (PR #222264)

[Folkert de Vries via cfe-commits]

================
@@ -71,6 +71,18 @@ ABIArgInfo SparcV8ABIInfo::classifyReturnType(QualType Ty) const {
   if (const auto *CT = Ty->getAs<ComplexType>())
     return classifyComplexType(CT, /*IsRet=*/true);
 
+  if (const auto *VT = Ty->getAs<VectorType>()) {
+    uint64_t Size = getContext().getTypeSize(Ty);
----------------
folkertdev wrote:

```suggestion
    uint64_t Size = getContext().getTypeSize(Ty);
    // Return float vectors and larger integer vectors indirectly.
```

given that it needs a merge, maybe add a comment here too?

https://github.com/llvm/llvm-project/pull/222264