Write a second program called cpuloop that runs a
mathematically intensive loop for a fixed number of iterations. Make
it take the number of iterations as an argument from the command line.
Calibrate the program so that you know how many iterations take about
3 seconds of CPU time. It should not print anything inside the loop.
This program will be CPU-bound; that is, its run time will be
primarily determined by how much CPU time it gets. Other programs
might be I/O-bound, meaning that their performance is determined by
the performance of one of the I/O systems, and relatively insensitive
to the amount of CPU that's available.
