btrfs-progs: add compat header for android

Provide stubs and compat macros for android build.

Signed-off-by: David Sterba <dsterba@suse.com>

androidcompat.h

@@ -0,0 +1,28 @@
+/*
+ * Compatibility layer for Android.
+ *
+ * Stub calls or alternate functions for pthreads.
+ */
+
+#ifndef __ANDROID_H__
+#define __ANDROID_H__
+
+#ifdef ANDROID
+
+#define pthread_setcanceltype(type, oldtype)	(0)
+#define pthread_setcancelstate(state, oldstate)	(0)
+
+#define pthread_cancel(ret)	pthread_kill((ret), SIGUSR1)
+
+typedef struct blkid_struct_probe *blkid_probe;
+
+#include <dirent.h>
+#define direct dirent
+
+#else	/* !ANDROID */
+
+#include <sys/dir.h>
+
+#endif	/* !ANDROID */
+
+#endif	/* __ANDROID_H__ */