IVGCVSW-3267 Add Arm NN front end support for the new Prelu Activation layer

 * Added new PreluLayer class
 * Made necessary changes to ILayerSupport, ILayerVisitor, etc.
 * Added unit tests

Change-Id: Ifcfb78e823bb5a245ed1dad15290d2f60115c882
Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>
diff --git a/src/armnnSerializer/Serializer.cpp b/src/armnnSerializer/Serializer.cpp
index 131bb95..012ed66 100644
--- a/src/armnnSerializer/Serializer.cpp
+++ b/src/armnnSerializer/Serializer.cpp
@@ -709,6 +709,12 @@
     CreateAnyLayer(fbPooling2dLayer.o, serializer::Layer::Layer_Pooling2dLayer);
 }
 
+void SerializerVisitor::VisitPreluLayer(const armnn::IConnectableLayer* layer,
+                                        const char* name)
+{
+    throw UnimplementedException("SerializerVisitor::VisitPreluLayer not yet implemented");
+}
+
 void SerializerVisitor::VisitQuantizeLayer(const armnn::IConnectableLayer *layer, const char *name)
 {
     auto fbQuantizeBaseLayer = CreateLayerBase(layer, serializer::LayerType::LayerType_Quantize);