fix resource leak in os.(*File).Close

Signed-off-by: Achille Roussel <achille.roussel@gmail.com>

src/syscall/syscall_libc_darwin.go

@@ -267,6 +267,14 @@ func Pipe2(fds []int, flags int) (err error) {
 	return
 }
 
+func closedir(dir uintptr) (err error) {
+	e := libc_closedir(unsafe.Pointer(dir))
+	if e != 0 {
+		err = getErrno()
+	}
+	return
+}
+
 func readdir_r(dir uintptr, entry *Dirent, result **Dirent) (err error) {
 	e1 := libc_readdir_r(unsafe.Pointer(dir), unsafe.Pointer(entry), unsafe.Pointer(result))
 	if e1 != 0 {

src/syscall/syscall_libc_darwin_amd64.go

@@ -17,6 +17,11 @@ import (
 //export fdopendir$INODE64
 func libc_fdopendir(fd int32) unsafe.Pointer
 
+// int closedir(struct DIR * buf);
+//
+//export closedir
+func libc_closedir(unsafe.Pointer) int32
+
 // int readdir_r(struct DIR * buf, struct dirent *entry, struct dirent **result);
 //
 //export readdir_r$INODE64

src/syscall/syscall_libc_darwin_arm64.go

@@ -11,6 +11,11 @@ import (
 //export fdopendir
 func libc_fdopendir(fd int32) unsafe.Pointer
 
+// int closedir(struct DIR * buf);
+//
+//export closedir
+func libc_closedir(unsafe.Pointer) int32
+
 // int readdir_r(struct DIR * buf, struct dirent *entry, struct dirent **result);
 //
 //export readdir_r