Auto merge of #8778 - sunfishcode:main, r=giraffate

Fix `cast_lossless` to avoid warning on `usize` to `f64` conversion.

Previously, the `cast_lossless` lint would issue a warning on code that
converted a `usize` value to `f64`, on 32-bit targets.

`usize` to `f64` is a lossless cast on 32-bit targets, however there is
no corresponding `f64::from` that takes a `usize`, so `cast_lossless`'s
suggested replacement does not compile.

This PR disables the lint in the case of casting from `usize` or `isize`.

Fixes #3689.

changelog: [`cast_lossless`] no longer gives wrong suggestion on usize,isize->f64

clippy_lints/src/casts/cast_lossless.rs

@@ -93,7 +93,7 @@ fn should_lint(
             } else {
                 64
             };
-            from_nbits < to_nbits
+            !is_isize_or_usize(cast_from) && from_nbits < to_nbits
         },
         (false, true) if matches!(cast_from.kind(), ty::Bool) && meets_msrv(msrv.as_ref(), &msrvs::FROM_BOOL) => true,
         (_, _) => {