Bug in string or AA handling

[Walter Bright]

Jari-Matti Mäkelä wrote:
> This code segfaults on linux with dmd 0.150 even with all debug-flags on:
> 
> import std.string, std.date, std.random;
> alias char[] String;
> 
> class Node {
>     String label;
>     Node[char] successors;

It does look like the AA problem with the key type not being a multiple 
size of a pointer size. A fix for this will go out in the next update.