swift234

Add in the option -disable-llvm-optzns to swift.

-disable-llvm-optzns in clang tells the frontend to do everything it would
normally do at lets say -O2, except run the actual LLVM IR passes on the
resulting IR. This is useful in the case where one wants to look at the result
of a non gauranteed SIL optimization pass at the IR level without llvm
optimizations applied.

Swift SVN r8594