Auto merge of #123440 - jhpratt:rollup-yat6crk, r=jhpratt

Rollup of 4 pull requests

Successful merges:

 - #122356 (std::rand: fix dragonflybsd after #121942.)
 - #123093 (Add a nice header to our README.md)
 - #123307 (Fix f16 and f128 feature gating on different editions)
 - #123401 (Check `x86_64` size assertions on `aarch64`, too)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 13 insertions, 7 deletions

diff --git a/library/std/src/sys/pal/unix/rand.rs b/library/std/src/sys/pal/unix/rand.rs
index c9ed6825f6c..d52c3254e5e 100644
--- a/library/std/src/sys/pal/unix/rand.rs
+++ b/library/std/src/sys/pal/unix/rand.rs
@@ -62,17 +62,23 @@ mod imp {
         unsafe { getrandom(buf.as_mut_ptr().cast(), buf.len(), libc::GRND_NONBLOCK) }
     }
 
-    #[cfg(any(
-        target_os = "espidf",
-        target_os = "horizon",
-        target_os = "freebsd",
-        target_os = "dragonfly",
-        netbsd10
-    ))]
+    #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "freebsd", netbsd10))]
     fn getrandom(buf: &mut [u8]) -> libc::ssize_t {
         unsafe { libc::getrandom(buf.as_mut_ptr().cast(), buf.len(), 0) }
     }
 
+    #[cfg(target_os = "dragonfly")]
+    fn getrandom(buf: &mut [u8]) -> libc::ssize_t {
+        extern "C" {
+            fn getrandom(
+                buf: *mut libc::c_void,
+                buflen: libc::size_t,
+                flags: libc::c_uint,
+            ) -> libc::ssize_t;
+        }
+        unsafe { getrandom(buf.as_mut_ptr().cast(), buf.len(), 0) }
+    }
+
     #[cfg(not(any(
         target_os = "linux",
         target_os = "android",