Use unsafe blocks in float.h implementation

src/header/float/mod.rs

@@ -2,6 +2,9 @@
 //!
 //! See <https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/float.h.html>.
 
+// TODO: set this for entire crate when possible
+#![deny(unsafe_op_in_unsafe_fn)]
+
 use crate::{
     header::_fenv::{FE_TONEAREST, fegetround},
     platform::types::c_int,
@@ -13,7 +16,7 @@ pub const FLT_RADIX: c_int = 2;
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/float.h.html>.
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn flt_rounds() -> c_int {
-    match fegetround() {
+    match unsafe { fegetround() } {
         FE_TONEAREST => 1,
         _ => -1,
     }