[pre-RFC] Compilation Configuration Representation

[tqchen]

[RFC] Composite Target

This is a follow-up RFC from [RFC] TVM Target Specification This RFC is discussed with @junrushao. In this RFC, we propose the way to represent a composite target. The motivation is that now we have multiple codegens contributed by the community members via BYOC targeting to specialized hardware and libraries, such as ARM ACL, ARM Ethos-N, TensorRT, and Vitis-AI. The main difference between those codegens and other TVM backends (e.g., LLVM, CUDA, OpenCL, etc) is that those specialized codegens…