message: Define the _fltused symbol in one lldb test as well, post-r352076.
diff: // This technique in general allows us to exercise most of LLDB's type
  // system without a running process.
  +// Define _fltused, since we're not linking against the MS C runtime, but use
  +// floats.
  +extern "C" int _fltused = 0;
  +
  template<typename T>
  struct MakeResult {
  static T result() {
  