Merge pull request rust-lang#3996 from devnexen/close_range_fbsd_upd

freebsd: add CLOSE_RANGE_CLOEXEC flag

Author: tgross35

libc-test/semver/freebsd.txt

@@ -264,6 +264,7 @@ CLOCK_UPTIME
 CLOCK_UPTIME_FAST
 CLOCK_UPTIME_PRECISE
 CLOCK_VIRTUAL
+CLOSE_RANGE_CLOEXEC
 CMGROUP_MAX
 CMSG_DATA
 CMSG_FIRSTHDR

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

@@ -4906,6 +4906,10 @@ pub const KCMP_FILES: ::c_int = 102;
 pub const KCMP_SIGHAND: ::c_int = 103;
 pub const KCMP_VM: ::c_int = 104;
 
+// sys/unistd.h
+
+pub const CLOSE_RANGE_CLOEXEC: ::c_uint = 1 << 2;
+
 pub const fn MAP_ALIGNED(a: ::c_int) -> ::c_int {
     a << 24
 }