[llvm] [DXIL] Add support for root signature flag element in DXContainer (PR #123147)

[Chris B via llvm-commits]

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@@ -254,11 +254,9 @@ Error DirectX::RootSignature::parse(StringRef Data) {
       support::endian::read<uint32_t, llvm::endianness::little>(Current);
   Current += sizeof(uint32_t);
 
-  Expected<uint32_t> MaybeVersion =
-      dxbc::RootSignatureValidations::validateVersion(VValue);
-  if (Error E = MaybeVersion.takeError())
-    return E;
-  Version = MaybeVersion.get();
+  if (dxbc::RootSignatureValidations::validateVersion(VValue))
+    return make_error<GenericBinaryError>("Invalid Root Signature Version");
----------------
llvm-beanz wrote:

These error strings are what get printed by LLVM if we ever hit this error condition. This message doesn't tell me what the actual error is.

Maybe something like (needs proper formatting):
```suggestion
    return make_error<GenericBinaryError>(Twine("Unsupported root signature version read: " + VValue);
```

https://github.com/llvm/llvm-project/pull/123147