Implement vcreate to start a process with a virtual private heap

[salekinsirajus]

This system call creates a “user” process with a virtual heap. The process’s heap must be private and exist in
the process’s own virtual memory space. Your implementation should use paging and a 4KB page size.

pid32 vcreate (void *funcaddr, uint32 ssize, pri16 priority, char *name, uint32 nargs, …)

All processes can still use the getmem system call to allocate shared heap space. This means implement it as a separate function(#6) so it can be called from anywhere.