There was a method for Xcode 4.x:
#define __AVAILABILITY_TOO_NEW __attribute__((deprecated(\"TOO NEW!\"))) __attribute__((weak_import))
#if __IPHONE_OS_VERS
I found some other information on the topic. This will redefine a different macro (NS_AVAILABLE_IOS). Perhaps it will work a bit better than
(Source https://www.albertopasca.it/whiletrue/xcode-warn-about-new-api-classes-and-methods/)
#import
#import
#if( 1 )
#define APICHECK_2_0( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_2_1( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_2_2( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_3_0( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_3_1( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_3_2( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_4_0( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_4_1( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_4_2( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_4_3( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_5_0( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#define APICHECK_5_1( _ios ) __attribute__((deprecated("UNAVAILABLE PRIOR TO 5.1")))
#define APICHECK_6_0( _ios ) __attribute__((deprecated("UNAVAILABLE PRIOR TO 6.0")))
#define APICHECK_6_1( _ios ) __attribute__((deprecated("UNAVAILABLE PRIOR TO 6.1")))
#define APICHECK_NA( _ios ) __OSX_AVAILABLE_STARTING(__MAC_NA, __IPHONE_##_ios)
#undef NS_AVAILABLE_IOS
#define NS_AVAILABLE_IOS(_ios) APICHECK_ ## _ios( _ios )
#undef NS_AVAILABLE
#define NS_AVAILABLE(_mac, _ios) APICHECK_ ## _ios( _ios )
#endif
You can use conditionals the same way as before (#if __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_6_0 etc). Note that I have not tested this because I don't have Xcode 5 on my machine yet. If you want to turn the warnings into errors you can use __attribute__((unavailable("UNAVAILABLE PRIOR TO 6.1"))) etc.
You can also try using this program, though it is paid. http://www.deploymateapp.com/