Rollup merge of rust-lang#146051 - LorrensP-2158466:miri-libstd-fix, r=RalfJung

Change std f32 test to pass under Miri

Adds `APPROX_DELTA` to 2 tests of `f32::log` reported in [#miri > Miri test-libstd Failure (2025-08)](https://rust-lang.zulipchat.com/#narrow/channel/269128-miri/topic/Miri.20test-libstd.20Failure.20.282025-08.29).

I changed 2 lines, the first one is the actual failure. The second one is precautionary.

Author: Zalathar

library/std/tests/floats/f32.rs

@@ -79,8 +79,8 @@ fn test_log() {
     let nan: f32 = f32::NAN;
     let inf: f32 = f32::INFINITY;
     let neg_inf: f32 = f32::NEG_INFINITY;
-    assert_approx_eq!(10.0f32.log(10.0), 1.0);
-    assert_approx_eq!(2.3f32.log(3.5), 0.664858);
+    assert_approx_eq!(10.0f32.log(10.0), 1.0, APPROX_DELTA);
+    assert_approx_eq!(2.3f32.log(3.5), 0.664858, APPROX_DELTA);
     assert_approx_eq!(1.0f32.exp().log(1.0f32.exp()), 1.0, APPROX_DELTA);
     assert!(1.0f32.log(1.0).is_nan());
     assert!(1.0f32.log(-13.9).is_nan());