Microsoft has open sourced the lib at: https://github.com/microsoft/DirectXShaderCompiler/tree/master/projects/dxilconv/lib/DxbcConverter
DEPRECATED. DXBC to DXIL (HLSL Bytecode to LLVM IR) using internal APIs.
Microsoft has open sourced the lib at: https://github.com/microsoft/DirectXShaderCompiler/tree/master/projects/dxilconv/lib/DxbcConverter