Userspace exec on redoxos should support storing process arguments

Admin tools like ps -ef on other *nix platforms will print the process arguments of running processes. This information is helpful to diagnose process behavior/how processes were launched. The redox kernel does not keep track of process arguments, these are set up and passed to processes by relibc's exec implementation. ps has no way to query process arguments today.

This information needs to ultimately end up in sys:/context to be available to ps and other tools.