Two problems with these lines of code:

 1. The "work" was not in the assert, so it was punishing the optimized release
 2. getNamedFunction is _very_ expensive in large programs.  It is not designed
    to be used like this, and was taking 7% of the execution time of the code
    generator on perlbmk.

Since the assert "can never fail", I'm just killing it.

llvm-svn: 11214