fixup! float: Use a shared assert_biteq! macro for tests

Author: tgross35

library/coretests/tests/floats/mod.rs

@@ -28,10 +28,11 @@ macro_rules! assert_biteq {
 
         // Hack to get the width from a value
         let bits = (l.to_bits() - l.to_bits()).leading_zeros();
+        let nl = if stringify!($($tt)*).is_empty() { "" } else { "\n" };
         assert!(
             l.to_bits() == r.to_bits(),
-            "{}\nl: {l:?} ({lb:#0width$x})\nr: {r:?} ({rb:#0width$x})",
-            format_args!($($tt)*),
+            "{msg}{nl}l: {l:?} ({lb:#0width$x})\nr: {r:?} ({rb:#0width$x})",
+            msg = format_args!($($tt)*),
             lb = l.to_bits(),
             rb = r.to_bits(),
             width = ((bits / 4) + 2) as usize,