* Cnstants are now global objects

* ConstantPools no longer exist
* Constants are global objects in the LLVM system
* Constants are structurally equilivant if they are pointer equilivant
* Support abstract & opaque types
* Support setName on constants even though they don't track names
* Constnats don't get copy ctors anymore
* ConstPoolVal::equals is no longer useful [use ptr equivalency]
* Support generic factory classes to create and maintain constants

llvm-svn: 460