vm/allot.hpp: Print more room info when allot() fails.
vm/allot.hpp: Print more room info when allot() fails.

This is to help debug win64.

Some interesting observations:

fails without any error:
factor.com -codeheap=74000

fails with VirtualAlloc error:
factor.com -codeheap=80000

factor/factor,AlexIljin/factor,mrjbq7/factor,AlexIljin/factor,tgunr/factor,mrjbq7/factor,AlexIljin/factor,factor/factor,bpollack/factor,AlexIljin/factor,factor/factor,AlexIljin/factor,mrjbq7/factor,tgunr/factor,bpollack/factor,bpollack/factor,bpollack/factor,bpollack/factor,mrjbq7/factor,factor/factor,tgunr/factor,mrjbq7/factor,AlexIljin/factor,tgunr/factor,tgunr/factor,factor/factor,AlexIljin/factor,mrjbq7/factor,tgunr/factor,bpollack/factor,bpollack/factor,factor/factor