#ifndef + if(debugging(x)) + errs() => debugs(x).

Simplify debug output from TESLA C++-land by replacing:
#ifndef NDEBUG
if (debugging("tesla.foo"))
  llvm::errs() << Message;
#endif

with:
debugs("tesla.foo") << Message;

If we're not debugging (based on a compile- or run-time decision), this call returns a reference to an llvm::raw_null_ostream, which does nothing when appended to.