dd5e502d4b
Update `ParamEnv` docs There is now a wealth of information in the dev guide about `ParamEnv` so we should explicitly link to it from the doc comments. I also added a caution against using `ParamEnv` and removed the comment about it being "suitable for type checking" as you should practically never use `ParamEnv::empty` for type checking r? `@compiler-errors`
For more information about how rustc works, see the rustc dev guide.