fix doc tests

Author: xonx4l

library/coretests/tests/floats/mod.rs

@@ -1,6 +1,7 @@
 use std::num::FpCategory as Fp;
 use std::ops::{Add, Div, Mul, Rem, Sub};
 
+#[doc(hidden)]
 trait TestableFloat: Sized {
     /// Unsigned int with the same size, for converting to/from bits.
     type Int;