Auto merge of #3399 - devnexen:fbsd_prot_max, r=JohnTitor

freebsd adding PROT_MAX|PROT_MAX_EXTRACT mmap flags

Author: bors

libc-test/semver/freebsd.txt

@@ -972,6 +972,8 @@ PROC_WX_MAPPINGS_PERMIT
 PROC_WXMAP_CTL
 PROC_WXMAP_STATUS
 PROC_WXORX_ENFORCE
+PROT_MAX
+PROT_MAX_EXTRACT
 PTHREAD_CREATE_DETACHED
 PTHREAD_CREATE_JOINABLE
 PTHREAD_MUTEX_ADAPTIVE_NP

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

@@ -4857,6 +4857,14 @@ f! {
         };
         ::mem::size_of::<sockcred2>() + ::mem::size_of::<::gid_t>() * ngrps
     }
+
+    pub fn PROT_MAX(x: ::c_int) -> ::c_int {
+        x << 16
+    }
+
+    pub fn PROT_MAX_EXTRACT(x: ::c_int) -> ::c_int {
+        (x >> 16) & (::PROT_READ | ::PROT_WRITE | ::PROT_EXEC)
+    }
 }
 
 safe_f! {