[Issue 18768] New: object.getArrayHash with custom toHash shouldn't just sum hashes of array elements

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18768

          Issue ID: 18768
           Summary: object.getArrayHash with custom toHash shouldn't just
                    sum hashes of array elements
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: druntime
          Assignee: nobody at puremagic.com
          Reporter: n8sh.secondary at hotmail.com

Currently:
```
    if(!hasCustomToHash(element))
        return hashOf(ptr[0 .. elementSize * count], 0);

    size_t hash = 0;
    foreach(size_t i; 0 .. count)
        hash += element.getHash(ptr + i * elementSize);
    return hash;
```

--