Expose tests for {f32,f64}.total_cmp in docs

Uncomment the helpful assert_eq! line, which is stripped out
completely in docs, and leaves the reader to mentally play
through the algorithm, or go to the playground and add a println!,
to see what the result will be.

(If these tests are known to fail on some platforms, is there
some mechanism to conditionalize this or escape the comments so
the assert_eq! source will be visible on the web?)

library/core/src/num/f32.rs

@@ -1385,9 +1385,9 @@ impl f32 {
     /// ];
     ///
     /// bois.sort_by(|a, b| a.weight.total_cmp(&b.weight));
-    /// # assert!(bois.into_iter().map(|b| b.weight)
-    /// #     .zip([-5.0, 0.1, 10.0, 99.0, f32::INFINITY, f32::NAN].iter())
-    /// #     .all(|(a, b)| a.to_bits() == b.to_bits()))
+    /// assert!(bois.into_iter().map(|b| b.weight)
+    ///     .zip([-5.0, 0.1, 10.0, 99.0, f32::INFINITY, f32::NAN].iter())
+    ///     .all(|(a, b)| a.to_bits() == b.to_bits()))
     /// ```
     #[stable(feature = "total_cmp", since = "1.62.0")]
     #[must_use]

library/core/src/num/f64.rs

@@ -1383,9 +1383,9 @@ impl f64 {
     /// ];
     ///
     /// bois.sort_by(|a, b| a.weight.total_cmp(&b.weight));
-    /// # assert!(bois.into_iter().map(|b| b.weight)
-    /// #     .zip([-5.0, 0.1, 10.0, 99.0, f64::INFINITY, f64::NAN].iter())
-    /// #     .all(|(a, b)| a.to_bits() == b.to_bits()))
+    /// assert!(bois.into_iter().map(|b| b.weight)
+    ///     .zip([-5.0, 0.1, 10.0, 99.0, f64::INFINITY, f64::NAN].iter())
+    ///     .all(|(a, b)| a.to_bits() == b.to_bits()))
     /// ```
     #[stable(feature = "total_cmp", since = "1.62.0")]
     #[must_use]