Clang scan-build 7 reports:

```
Tests/CMakeLib/testUTF8.cxx:12:3: warning: 4th function call argument is an uninitialized value
  printf("[0x%02X,0x%02X,0x%02X,0x%02X]", static_cast<int>(d[0]),
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

Manual tracing of all call sites shows that all values are initialized.