[new AA] aaLiteral compiler support

This is a dmd part of the new AA implementation. 
This PR depends on D-Programming-Language/druntime#1046 and uses new aaLiteral version (with arrays of keys and arguments)

I've found a solution: I removed `static immutable AssociativeArrayHandle handle = ...` and create a template
```
private template getAAHandle(Key, Value)
{
    __gshared immutable AssociativeArrayHandle getAAHandle = AssociativeArrayHandle(&AssociativeArray!(Key, Value)._aaLen,
                                   &AssociativeArray!(Key, Value)._aaGetZ,
                                   &AssociativeArray!(Key, Value)._aaGetRvalueX,
                                   &AssociativeArray!(Key, Value)._aaDelX,
                                   &AssociativeArray!(Key, Value)._aaApply,
                                   &AssociativeArray!(Key, Value)._aaApply2,
                                   &AssociativeArray!(Key, Value)._aaEqual,
                                   &AssociativeArray!(Key, Value)._aaValues,
                                   &AssociativeArray!(Key, Value)._aaKeys,
                                   &AssociativeArray!(Key, Value)._aaRehash,
                                   &AssociativeArray!(Key, Value)._aaDup,
                                   &AssociativeArray!(Key, Value)._aaRange,
                                   &AssociativeArray!(Key, Value)._aaRangeEmpty,
                                   &AssociativeArray!(Key, Value)._aaRangeFrontKey,
                                   &AssociativeArray!(Key, Value)._aaRangeFrontValue,
                                   &AssociativeArray!(Key, Value)._aaRangePopFront,
                                   &AssociativeArray!(Key, Value)._aaGetHash);
}
``` 
Now I use it to get a handle pointer. Now It start works, but I faced with another problem:
In some cases (I do not understand the logic), I have got a undefined reference to Test5.init. I replaced it with templated struct with zero arguments and looks like it works. This error happens only when program is compiled with `-unittest`. Looks like it is dmd bug.