Bad use suggestion for RawFloat

[lukaslueg]

fn main() {
 let _ = f32::INFINITY;
}

will error with

  |
3 |  let _ = f32::INFINITY;
  |          ^^^^^^^^^^^^^ associated item not found in `f32`
  |
  = help: items from traits can only be used if the trait is in scope
help: the following trait is implemented but not in scope, perhaps add a `use` for it:
  |
2 | use core::num::dec2flt::rawfp::RawFloat;

The suggestion is both unhelpful and wrong at the same time. Using use core::num::dec2flt::rawfp::RawFloat; would cause a name-error. What we really want here is simply

use std::f32;

[Centril]

cc @estebank

[estebank]

Closing as duplicate of #26760.