BasicBlock tracking breaks trunk

Hello,

I just wanted to let whomever is working on BasicBlock Tracking on trunk that the initial builds of LLVM need to be able to build on GCC as well as LLVM-GCC so don't assume that --emit-llvm will be available at the initial compile. I tried building a release build of LLVM with todays head and yesterdays and it failed in the same place on both.

Thanks,

--Sam