read/write writable in the pagetable right away instead of waiting for
a pagefault. minor optimization.
some a sanity check of SLAB-allocated pointers.
vm gets its own _exit and __exit like PM, so the stock (library) panic works.
their own fully fledged virtual address space and freeing
their pre-allocated heap+stack area (necessary to let memory
driver map in arbitrary areas of memory for /dev/mem without
sys_vm_map)
- small optimization preallocating memory on exec
- finished VR_DIRECT physical mapping code
