[clang] [llvm] [HLSL] Update Frontend to support version 1.2 of root signature (PR #160616)

[Justin Bogner via llvm-commits]

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@@ -550,7 +550,7 @@ class LangOptions : public LangOptionsBase {
 
   /// The HLSL root signature version for dxil.
   llvm::dxbc::RootSignatureVersion HLSLRootSigVer =
-      llvm::dxbc::RootSignatureVersion::V1_1;
+      llvm::dxbc::RootSignatureVersion::V1_2;
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bogner wrote:

Does this need to stay as `V1_1` since we aren't changing the default here? This might be a good place to comment that we default to v1.1 to match dxc as well.

https://github.com/llvm/llvm-project/pull/160616