[clang] [CIR] Upstream TypeInfo attribute (PR #159426)

[Henrich Lauko via cfe-commits]

================
@@ -521,6 +522,21 @@ mlir::Value CIRAttrToValue::visitCirAttr(cir::GlobalViewAttr globalAttr) {
   llvm_unreachable("Expecting pointer or integer type for GlobalViewAttr");
 }
 
+// TypeInfoAttr visitor.
+mlir::Value CIRAttrToValue::visitCirAttr(cir::TypeInfoAttr typeinfoAttr) {
+  mlir::Type llvmTy = converter->convertType(typeinfoAttr.getType());
+  mlir::Location loc = parentOp->getLoc();
+  mlir::Value result = mlir::LLVM::UndefOp::create(rewriter, loc, llvmTy);
+
+  for (auto [idx, elt] : llvm::enumerate(typeinfoAttr.getData())) {
+    mlir::Value init = visit(elt);
+    result =
+        mlir::LLVM::InsertValueOp::create(rewriter, loc, result, init, idx);
+  }
+
+  return result;
+}
----------------
xlauko wrote:

```suggestion
mlir::Value CIRAttrToValue::visitCirAttr(cir::TypeInfoAttr typeInfoAttr) {
  mlir::Type llvmTy = converter->convertType(typeInfoAttr.getType());
  mlir::Location loc = parentOp->getLoc();
  mlir::Value result = mlir::LLVM::UndefOp::create(rewriter, loc, llvmTy);

  for (auto [idx, elt] : llvm::enumerate(typeInfoAttr.getData())) {
    mlir::Value init = visit(elt);
    result =
        mlir::LLVM::InsertValueOp::create(rewriter, loc, result, init, idx);
  }

  return result;
}
```

https://github.com/llvm/llvm-project/pull/159426