[llvm] [DirectX] Adding support for Root Descriptors in obj2yaml/yaml2obj (PR #137259)

[Finn Plummer via llvm-commits]

================
@@ -149,6 +152,24 @@ struct RootConstantView : RootParameterView {
   }
 };
 
+struct RootDescriptorView : RootParameterView {
+  static bool classof(const RootParameterView *V) {
+    return (V->Header.ParameterType ==
+                llvm::to_underlying(dxbc::RootParameterType::CBV) ||
+            V->Header.ParameterType ==
+                llvm::to_underlying(dxbc::RootParameterType::SRV) ||
+            V->Header.ParameterType ==
+                llvm::to_underlying(dxbc::RootParameterType::UAV));
+  }
+
+  llvm::Expected<dxbc::RST0::v1::RootDescriptor> read(uint32_t Version) {
+    if (Version == 1)
----------------
inbelic wrote:

```suggestion
    if (Version == 0)
```
A little concerning that this passes the testcases because IIUC this is reading the opposite version of what would be expected

https://github.com/llvm/llvm-project/pull/137259