Feature Gate Checking

src/feature-gate-ck.md

26576f87add49d6c046bad6c96a1f2cc94dc6c39828dfa2f0000000300000072

# Feature Gate Checking

**TODO**: this chapter [#1158](https://github.com/rust-lang/rustc-dev-guide/issues/1158)

Chunks

9ca07986 (1st chunk of `src/feature-gate-ck.md`)

Title: Feature Gate Checking - TODO

Summary

This section on feature gate checking is a placeholder and needs to be written. A GitHub issue is linked for tracking its progress.