525438b6a9
Strict provenance lints See #95488. This PR introduces two unstable (allow by default) lints to which lint on int2ptr and ptr2int casts, as the former is not possible in the strict provenance model and the latter can be written nicer using the `.addr()` API. Based on an initial version of the lint by ```@Gankra``` in #95199.
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.