TypeInfo methods getHash, compare, equals unimplemented for AA, function and delegate

this is connected to #1066 and #795, see the progress there.

(In [4400]) shared typeinfo and utils between compilers. better hashing closes #795 , refs #988

I have improved typeinfo.

AA now have hashing and isEqual methods, but no compare method. In fact I cannot think of an efficient way of defining a total order on AA. the only think that I can think of is: order keys, compare the smallest, if equal compare the values, if equal drop key and repeat. In theory one can first use the hash, then the number of elements, and only if these two are equal proceed with the comparison (or maybe somehow use the partial hashes during the comparison, and probably treat exact equality as special case, to speed things up). Still this looks quite inefficient.

If someone proposes a good comparison algorithm I will use it, for now it is "won't fix"