No warnings or errors if a UEnum has Bitflags metadata, but no Flags flag.

The problem here isn't obvious: the native enum, EAnotherEnum, is missing the Flags flag for the UEnum. As a result, K2Node_GetEnumeratorNameAsString returns the max enum when it gets a combined flag value.

We likely can't fix this issue in UHT, but we should issue either a BP compiler warning or runtime error here.

1. Drag Issue5_BP into the level.
2. Start PIE.
3. Observe screen prints "E Another Enum Max".
4. Expected behavior: screen prints "One | Two".