Rollup merge of #59880 - solson:transmute-float, r=alexcrichton

Rollup merge of #59880 - solson:transmute-float, r=alexcrichton

Remove note about transmute for float bitpatterns.

This particular usecase has been safely abstracted in these `std` functions: [f32::to_bits](https://doc.rust-lang.org/std/primitive.f32.html#method.to_bits), [f32::from_bits](https://doc.rust-lang.org/std/primitive.f32.html#method.from_bits), [f64::to_bits](https://doc.rust-lang.org/std/primitive.f64.html#method.to_bits), [f64::from_bits](https://doc.rust-lang.org/std/primitive.f64.html#method.from_bits). So, I think we shouldn't recommend an unnecessary use of `unsafe` here anymore.