Why not use the address of the TypeInfo symbol as TypeInfo.toHash()?

[Walter Bright via Digitalmars-d]

On 3/3/2016 4:29 PM, Yuxuan Shui wrote:
> After linking each _DxxTypeInfo_yyyy__initZ symbol should have a unique address,
> so why are we using hash of type name as TypeInfo.toHash()?
> I don't think this has anything to do with compacting GC. Is there something I'm
> missing?

Because when working with DLLs (shared libraries) there may be more than one 
TypeInfo per type.