Project ZeroTangent to natural tangent for some number types#574

ToucheSir wants to merge 2 commits intoJuliaDiff:mainJuliaDiff/ChainRulesCore.jl:mainfrom

ToucheSir:bc/project-num-zerotangentToucheSir/ChainRulesCore.jl:bc/project-num-zerotangentCopy head branch name to clipboard