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

[Sarah Spall via llvm-commits]

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@@ -580,7 +585,28 @@ struct ProgramSignatureElement {
 
 static_assert(sizeof(ProgramSignatureElement) == 32,
               "ProgramSignatureElement is misaligned");
+namespace RST0 {
+namespace v0 {
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spall wrote:

> @damyanp @spall @inbelic @bogner I remember one detail, DXC uses the versions as 1 and 2: https://github.com/microsoft/DirectXShaderCompiler/blob/1198c30f05ed944873ca55e89970fae407e2aacc/include/dxc/DxilRootSignature/DxilRootSignature.h#L91C1-L92C1. The version is part of the binary container, and it will lead to the parsing of several fields, I am not sure if we should change that here, since I would still need to read and write 1 and 2 as the values identifying the version, I could change those, by doing something like `read(&version); version --;` and `write(++version);` but it seems to be adding unnecessary complexity IMHO. Thoughts ?

I'm not sure I understand this message, but what I was suggesting, and what I believe @damyanp was suggesting, is that in this PR you make the namespaces match the version naming convention. So v0 -> v1 and v1 -> v2.

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