Add TEMP_FAILURE_RETRY macro for darwin

Darwin doesn't define the TEMP_FAILURE_RETRY macro in unistd.h so we
need to add it everywhere. Joy!

(cherry picked from commit ec90f1dc11)

Change-Id: Ida554fc65193672cc4616dec79e6282e06cc1b28

adb/sysdeps.h

@@ -274,6 +274,21 @@ static __inline__  int  adb_is_absolute_host_path( const char*  path )
 #include <string.h>
 #include <unistd.h>
 
+/*
+ * TEMP_FAILURE_RETRY is defined by some, but not all, versions of
+ * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's
+ * not already defined, then define it here.
+ */
+#ifndef TEMP_FAILURE_RETRY
+/* Used to retry syscalls that can return EINTR. */
+#define TEMP_FAILURE_RETRY(exp) ({         \
+    typeof (exp) _rc;                      \
+    do {                                   \
+        _rc = (exp);                       \
+    } while (_rc == -1 && errno == EINTR); \
+    _rc; })
+#endif
+
 #define OS_PATH_SEPARATOR '/'
 #define OS_PATH_SEPARATOR_STR "/"