Add a Lint for Pointer to Integer Transmutes in Consts Fixes #87525 This PR adds a MirLint for pointer to integer transmutes in const functions and associated consts. The implementation closely follows this comment: https://github.com/rust-lang/rust/pull/85769#issuecomment-880969112. More details about the implementation can be found in the comments. Note: This could break some sound code as mentioned by RalfJung in https://github.com/rust-lang/rust/pull/85769#issuecomment-886491680: > ... technically const-code could transmute/cast an int to a ptr and then transmute it back and that would be correct -- so the lint will deny some sound code. Does not seem terribly likely though. References: 1. https://doc.rust-lang.org/std/mem/fn.transmute.html 2. https://doc.rust-lang.org/reference/items/associated-items.html#associated-constants