Review request for 8017084: Use spill properties for large object literals

[Hannes Wallnoefer]

Please review JDK-8017084: Use spill properties for large object literals:

http://cr.openjdk.java.net/~hannesw/8017084/

This adds a SpillObjectCreator to allow creation of large/huge object 
literals in constant time. It also gives Richards a 20% boost by trying 
to use the right structure class for the number of properties assigned 
in a constructor (although Marcus and Attila will probably hate me for 
adding a mutable set to FunctionNode).

Hannes