compositor: work around missing SOCK_CLOEXEC

Android does not have SOCK_CLOEXEC, so implement a wrapper that falls
back.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
diff --git a/shared/os-compatibility.h b/shared/os-compatibility.h
new file mode 100644
index 0000000..77e8672
--- /dev/null
+++ b/shared/os-compatibility.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright © 2012 Collabora, Ltd.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef OS_COMPATIBILITY_H
+#define OS_COMPATIBILITY_H
+
+int
+os_socketpair_cloexec(int domain, int type, int protocol, int *sv);
+
+#endif /* OS_COMPATIBILITY_H */