Cleanup lower_generics_mut and make span be the bound itself Closes #86298 (supersedes those changes) r? `@cjgillot` since you reviewed the other PR (Used wrong branch for #89338)
Cleanup lower_generics_mut and make span be the bound itself Closes #86298 (supersedes those changes) r? `@cjgillot` since you reviewed the other PR (Used wrong branch for #89338)