[clang] [llvm] [HLSL][RootSignature] Add `hlsl-rootsig-ver` option to specify root signature version (PR #144813)

[Justin Bogner via llvm-commits]

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@@ -5179,6 +5179,8 @@ class HLSLRootSignatureDecl final
                                     llvm::hlsl::rootsig::RootElement> {
   friend TrailingObjects;
 
+  llvm::dxil::RootSignatureVersion RootSigVer;
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bogner wrote:

This is a member of a HLSLRootSignatureDecl - it can probably just be called Version.

https://github.com/llvm/llvm-project/pull/144813