Clang UPC: 3.2 update

Recently, the Clang/LLVM version 3.2 release branch was
merged into the clang-upc and llvm-upc projects on Github.
Also some bugs relating to building Clang UPC on the Mac
and using newer versions of Cmake have been fixed.

Details follow.

- Gary Funck

Clang UPC: A UPC Compiler based upon Clang/LLVM