MLCE-328 Serializer/Deserializer does not support Signed64

 * Added support for Signed64 to flatbuffer's schema & updated source tree
 * Added support for Signed64 to TFLite Delegate
 * Added support for Signed64 to Serializer
 * Added support for Signed64 to Deserializer
 * Added unit test for ArgMinMax to Deserializer
 * Deprecated m_Output_Type from the ArgMinMaxDescriptor: the output type
   is solely determined by the DataType of the output Tensor
 * Fixed issue where RefArgMinMaxWorkload could output data using
   the wrong DataType
 * Added Signed64 to RefLayerSupport::IsArgMinMaxSupported as a supported
   type

Signed-off-by: Mike Kelly <mike.kelly@arm.com>
Signed-off-by: Matthew Sloyan <matthew.sloyan@arm.com>
Change-Id: Ib622c052a1f8aa3e658262f8bde5a6881a8cbe10
diff --git a/src/armnnSerializer/test/SerializerTests.cpp b/src/armnnSerializer/test/SerializerTests.cpp
index d7c10cb..9d44354 100644
--- a/src/armnnSerializer/test/SerializerTests.cpp
+++ b/src/armnnSerializer/test/SerializerTests.cpp
@@ -76,11 +76,11 @@
     deserializedNetwork->ExecuteStrategy(verifier);
 }
 
-BOOST_AUTO_TEST_CASE(SerializeArgMinMax)
+void SerializeArgMinMaxTest(armnn::DataType dataType)
 {
     const std::string layerName("argminmax");
     const armnn::TensorInfo inputInfo({1, 2, 3}, armnn::DataType::Float32);
-    const armnn::TensorInfo outputInfo({1, 3}, armnn::DataType::Signed32);
+    const armnn::TensorInfo outputInfo({1, 3}, dataType);
 
     armnn::ArgMinMaxDescriptor descriptor;
     descriptor.m_Function = armnn::ArgMinMaxFunction::Max;
@@ -107,6 +107,16 @@
     deserializedNetwork->ExecuteStrategy(verifier);
 }
 
+BOOST_AUTO_TEST_CASE(SerializeArgMinMaxSigned32)
+{
+    SerializeArgMinMaxTest(armnn::DataType::Signed32);
+}
+
+BOOST_AUTO_TEST_CASE(SerializeArgMinMaxSigned64)
+{
+    SerializeArgMinMaxTest(armnn::DataType::Signed64);
+}
+
 BOOST_AUTO_TEST_CASE(SerializeBatchNormalization)
 {
     const std::string layerName("batchNormalization");