// Can a be converted to b?

// score 0 = exact match
// score Int.MAX_VALUE = no match
// score 1 = conversion needed (boxing/unboxing or non-primitve widening)
// score -2 = primitive widening needed

static int typeConversionScoreWithUnboxing(Class a, Class b) {
  int score = typeConversionScore(a, b);
  if (score == 0 || score == 1) ret score;
  
  Class aPrim = boxedToPrimitiveType(a);
  if (aPrim != null) {
    int score2 = typeConversionScore(aPrim, b);
    if (score2 == 0) ret 1;
    else if (score2 != Int.MAX_VALUE) ret score2;
  }
  ret score;
}

Began life as a copy of #1034747