* Clean up data structures [AllocDSNode -> DSNode]

* TransformFunctionInfo now has call field form field mapping.  May be
  removed in the future.
* Moved the computation of "Scalars" into transformFunctionBody so
  transformFunction didn't have to recompute it.
* Implement the node mapping calculation in preparation to calculate
  PoolDescriptors to pass to transformFunctionBody
* Print out the node mapping [it looks right!]
* Other minor changes

llvm-svn: 2056