Made changes necessary to make flang compile with TOT llvm and independent of clang.

I made the changes necessary to make flang compile with TOT llvm.

I also created a flang-tablegen based off of TOT clang-tablegen. Thus flang is no longer dependent on clang.

I also added a CMake build chain. (Was going to do this in a different pull request, but I am not the best with github... =/)

Michael