Auto merge of #2479 - devnexen:fbsd_copy_file_range, r=Amanieu

freebsd 13 add copy_file_range api compatible with linux's glibc wrapper

Author: bors

src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs

@@ -290,6 +290,15 @@ extern "C" {
         mask: *const ::domainset_t,
         policy: ::c_int,
     ) -> ::c_int;
+
+    pub fn copy_file_range(
+        infd: ::c_int,
+        inoffp: *mut ::off_t,
+        outfd: ::c_int,
+        outoffp: *mut ::off_t,
+        len: ::size_t,
+        flags: ::c_uint,
+    ) -> ::ssize_t;
 }
 
 #[link(name = "kvm")]