Nicked from audio/spotifyd

Index: modcargo-crates/aws-lc-sys-0.29.0/aws-lc/crypto/fipsmodule/bcm.c
--- modcargo-crates/aws-lc-sys-0.29.0/aws-lc/crypto/fipsmodule/bcm.c.orig
+++ modcargo-crates/aws-lc-sys-0.29.0/aws-lc/crypto/fipsmodule/bcm.c
@@ -16,6 +16,10 @@
 #define _GNU_SOURCE  // needed for syscall() on Linux.
 #endif
 
+#if !defined(_BSD_SOURCE)
+#define _BSD_SOURCE  // needed for arc4random_buf() and bsd-style u_foo types
+#endif
+
 #include <openssl/crypto.h>
 
 #include <stdlib.h>
