Fix OSX10.9 build with filesystem patch...

Found here https://svn.boost.org/trac/boost/attachment/ticket/10591/boost-fs-fchmodat-darwin.patch

Author: dcwhite

libs/filesystem/src/operations.cpp

@@ -1400,20 +1400,26 @@ namespace detail
     else if (prms & remove_perms)
       prms = current_status.permissions() & ~prms;
 
-    // Mac OS X Lion and some other platforms don't support fchmodat().
-    // Solaris (SunPro and gcc) only support fchmodat() on Solaris 11 and higher,
-    // and a runtime check is too much trouble.
-    // Linux does not support permissions on symbolic links and has no plans to
+
+    // OS X <10.10, iOS <8.0 and some other platforms don't support fchmodat(). 
+    // Solaris (SunPro and gcc) only support fchmodat() on Solaris 11 and higher, 
+    // and a runtime check is too much trouble. 
+    // Linux does not support permissions on symbolic links and has no plans to 
     // support them in the future.  The chmod() code is thus more practical,
     // rather than always hitting ENOTSUP when sending in AT_SYMLINK_NO_FOLLOW.
     //  - See the 3rd paragraph of
     // "Symbolic link ownership, permissions, and timestamps" at:
     //   "http://man7.org/linux/man-pages/man7/symlink.7.html"
     //  - See the fchmodat() Linux man page:
     //   "http://man7.org/linux/man-pages/man2/fchmodat.2.html"
-#   if defined(AT_FDCWD) && defined(AT_SYMLINK_NOFOLLOW) \
-      && !(defined(__SUNPRO_CC) || defined(__sun) || defined(sun)) \
-      && !(defined(linux) || defined(__linux) || defined(__linux__))
+
+#   if defined(AT_FDCWD) && defined(AT_SYMLINK_NOFOLLOW) \ 
+       && !(defined(__SUNPRO_CC) || defined(__sun) || defined(sun)) \ 
+       && !(defined(linux) || defined(__linux) || defined(__linux__)) \ 
+       && !(defined(__MAC_OS_X_VERSION_MIN_REQUIRED) \ 
+       && __MAC_OS_X_VERSION_MIN_REQUIRED < 101000) \ 
+       && !(defined(__IPHONE_OS_VERSION_MIN_REQUIRED) \ 
+       && __IPHONE_OS_VERSION_MIN_REQUIRED < 80000) 
       if (::fchmodat(AT_FDCWD, p.c_str(), mode_cast(prms),
            !(prms & symlink_perms) ? 0 : AT_SYMLINK_NOFOLLOW))
 #   else  // fallback if fchmodat() not supported