Run LIBC tests in stability mode

And the second one is stability mode - for testing the libc stability. In this case you should put the number of cycles (for example, to run 1000 cycles - ./test-script.sh 1000). And now after script is finished the common log will be placed to the /var/tmp/libc-stability.<ISO TIME>.txt file, and you will find logs about separate cycles in libc-test.<N>.txt form in the /var/tmp folder, where <N> - is a cycle number.