also change std tests in core

Author: LorrensP-2158466

library/core/src/num/f32.rs

@@ -1879,7 +1879,7 @@ pub mod math {
     ///
     /// let x = 2.0_f32;
     /// let abs_difference = (f32::math::powi(x, 2) - (x * x)).abs();
-    /// assert!(abs_difference <= 1e-4);
+    /// assert!(abs_difference <= 1e-5);
     ///
     /// assert_eq!(f32::math::powi(f32::NAN, 0), 1.0);
     /// ```
@@ -1942,8 +1942,8 @@ pub mod math {
     /// let abs_difference_x = (f32::math::abs_sub(x, 1.0) - 2.0).abs();
     /// let abs_difference_y = (f32::math::abs_sub(y, 1.0) - 0.0).abs();
     ///
-    /// assert!(abs_difference_x <= 1e-4);
-    /// assert!(abs_difference_y <= 1e-4);
+    /// assert!(abs_difference_x <= 1e-6);
+    /// assert!(abs_difference_y <= 1e-6);
     /// ```
     ///
     /// _This standalone function is for testing only.
@@ -1988,7 +1988,7 @@ pub mod math {
     /// // x^(1/3) - 2 == 0
     /// let abs_difference = (f32::math::cbrt(x) - 2.0).abs();
     ///
-    /// assert!(abs_difference <= 1e-4);
+    /// assert!(abs_difference <= 1e-6);
     /// ```
     ///
     /// _This standalone function is for testing only.