fix getShapedFloat with APFloat value (#471)

- fix `getShapedValue` in ONNXToStablehloCommon to support APFloat with
fp16 input

frontends/onnx-frontend/third_party/patches/OnnxMlirONNXToStablehloCommon.patch

@@ -0,0 +1,27 @@
+diff --git a/src/Conversion/ONNXToStablehlo/ONNXToStablehloCommon.hpp b/src/Conversion/ONNXToStablehlo/ONNXToStablehloCommon.hpp
+index 832e72b9..3d8e1d7f 100644
+--- a/src/Conversion/ONNXToStablehlo/ONNXToStablehloCommon.hpp
++++ b/src/Conversion/ONNXToStablehlo/ONNXToStablehloCommon.hpp
+@@ -71,14 +71,20 @@ Value getShapedFloat(Location loc, ConversionPatternRewriter &rewriter,
+     const T &value, Value &inp) {
+   Value broadcastedValue;
+   ShapedType inpType = inp.getType().cast<ShapedType>();
++  float f32Value;
++  if constexpr (std::is_same_v<APFloat, T>) {
++    f32Value = cast<APFloat>(value).convertToFloat();
++  } else {
++    f32Value = value;
++  }
+   if (inpType.hasStaticShape())
+     broadcastedValue = rewriter.create<stablehlo::ConstantOp>(
+         loc, DenseElementsAttr::get(inpType,
+-                 rewriter.getFloatAttr(inpType.getElementType(), value)));
++                 rewriter.getFloatAttr(inpType.getElementType(), f32Value)));
+   else {
+     Type elemType = inpType.getElementType();
+     Value floatValue = rewriter.create<stablehlo::ConstantOp>(
+-        loc, rewriter.getFloatAttr(elemType, value));
++        loc, rewriter.getFloatAttr(elemType, f32Value));
+     Value shape = rewriter.create<shape::ShapeOfOp>(loc, inp);
+     broadcastedValue = rewriter.create<stablehlo::DynamicBroadcastInDimOp>(
+         loc, inpType, floatValue, shape, rewriter.getI64TensorAttr({}));