[RFC] Throwing an exception with null pointers

[Walter Bright]

The focus of safe code in D is preventing memory corruption, not null pointer 
dereference seg faults or other programming bugs.

A null pointer deference may be a symptom of memory corruption or some logic 
bug, but it does not cause memory corruption.

D has many aspects that reduce the likelihood of bugs (such as no variable 
shadowing), but that is not what safe is about.

(Yes I know that if there's a constant offset to a null pointer larger than the 
guard page, it can cause memory corruption.)