Fix InterpOne's output for predicted types

We were always pushing the output type onto the simulated stack,
effectively passing it as an asserted type, even when the type came
from type prediction.

hphp/runtime/vm/jit/hhbctranslator.cpp

@@ -3357,6 +3357,8 @@ Type HhbcTranslator::interpOutputType(const NormalizedInstruction& inst) const {
     return t.isBoxed() ? t : boxType(t);
   };
 
+  if (inst.outputPredicted) return Type::Gen;
+
   auto outFlag = getInstrInfo(inst.op()).type;
   if (outFlag == OutFInputL) {
     outFlag = inst.preppedByRef ? OutVInputL : OutCInputL;