message: Add int16 and uint16 to the type constraint of tfl.fully_connected
  For the fully_connected layer, we have seen FakeQuant* with 16bits are used in
  the training models, so we should add this to the op type constraint to
  quantize these models.
diff: @@ -138,6 +138,8 @@ class TFL_Int8UniformQuantizedType<int zero_pt, int smantissa, int sexp>
  // operand's tensor types.
  def TFL_QUI8 : TFL_QuantizedType<"Uniform", [8], 0>;
  def TFL_QI8 : TFL_QuantizedType<"Uniform", [8], 1>;
  +def TFL_QUI16 : TFL_QuantizedType<"Uniform", [16], 0>;
  +def TFL_QI16 : TFL_QuantizedType<"Uniform", [16], 1>;
  def TFL_QUI32 : TFL_QuantizedType<"Uniform", [32], 0>;
  def TFL_QI32 : TFL_QuantizedType<"Uniform", [32], 1>;
  @@ -613,8 +615,8 @@ def TFL_FullyConnectedOp : TFL_Op<"fully_connected", [
  let summary = "Fully connected op";
  let arguments = (ins
  - TensorOf<[F32, TFL_QI8, TFL_QUI8]>:$input,
  - TensorOf<[F32, TFL_QI8, TFL_QUI8]>:$filter,
  + TensorOf<[F32, TFL_QI8, TFL_QUI8, TFL_QI16, TFL_QUI16]>:$input,
  + TensorOf<[F32, TFL_QI8, TFL_QUI8, TFL_QI16, TFL_QUI16]>:$filter,
  TFL_TensorOfOrNone<[F32, TFL_QI32, TFL_QUI32]>:$bias,
  TFL_AFAttr:$fused_activation_function,
  @@ -624,7 +626,7 @@ def TFL_FullyConnectedOp : TFL_Op<"fully_connected", [
  // Depending on the weights format, this op can have one or two outputs.
  let results = (outs
  - Variadic<TensorOf<[F32, TFL_QI8, TFL_QUI8]>>:$output
  + Variadic<TensorOf<[F32, TFL_QI8, TFL_QUI8, TFL_QI16, TFL_QUI16]>>:$output
  );
  let hasOptions = 1;
  