Support IDxcContainerReflection on Linux

[manon-traverse]

IDxcContainerReflection is currently only implemented on the Windows build, since the headers d3d11shader.h and d3d12shader.h are included. These headers could be added to this repo for Linux support. (We have already done this for d3d12shader.h in Rust.)

The use case for this feature is that I would like to run reflection during offline shader compilation on a Linux server.

I am willing to open a PR for this, but would like to know if this is something that the maintainers would like to support or not.

DirectXShaderCompiler/lib/HLSL/DxilContainerReflection.cpp

Line 39 in 2dc067b

#ifdef LLVM_ON_WIN32

[gongminmin]

Or, take the open-sourced version of d3d12shader.h from DirectX-Headers?