hack on @safe functions

[Pavel]

Some suggesting to compiler checking for that case.

If talking about Linux OS it reserves first page (4kb on 32bit 
cpu, 8kb on 64) for null fault case (try to dereference pointer 
in that memory addresses will cause segmentation fault or smth 
like this).

So compiler can check (at compile time) each structure field 
access for  dereference with ofset > OS page size add code for 
check pointer of structure for null. Or when trying to get 
pointer of field that is in the range of page size, but field 
type size + ofset of this field > page size.

In this solution there will be very little overhead cause it is 
very rare case that structures have size > page size.

Sorry for my bad english. :)