fix iOS crash on device with AIR SDK 15

add "useLegacyAOT no" support
'var pooledCommands:Vector.<PooledCommand>;'
'if(commandPools[commandClass]) {'
'	pooledCommands = commandPools[commandClass];'
'	if(pooledCommands.length > 0) {'
'		command = pooledCommands.shift();'
'	}'
'}'
'if(command == null) {'
'	// code to create new command....'
'}'