Better diagnostics for null classes dereferencing

[kdevel]

On Tuesday, 10 July 2018 at 20:10:54 UTC, Adam D. Ruppe wrote:
> On Tuesday, 10 July 2018 at 19:01:22 UTC, Per Nordlöw wrote:
[...]
> Run the program in a debugger, or run `ulimit -c unlimited` to 
> enable core dumps [...]

Works for null ptr deref but how do I enforce core dumps in this 
code:

dumpme2.d
---
void main ()
{
    int [1] a;
    auto s = a[2 .. $];
}
---