Fix clippy::deprecated_cfg_attr on compiler_builtins

Author: Amjad50

src/math/exp2.rs

@@ -28,7 +28,7 @@ use super::scalbn;
 
 const TBLSIZE: usize = 256;
 
-#[cfg_attr(rustfmt, rustfmt_skip)]
+#[rustfmt::skip]
 static TBL: [u64; TBLSIZE * 2] = [
     //  exp2(z + eps)          eps
     0x3fe6a09e667f3d5d, 0x3d39880000000000,