IVGCVSW-5787 Add/Update Execute() implementations in RefActivationWorkload

 * Added multithreaded StridedSliceEndToEndTest

Signed-off-by: Finn Williams <Finn.Williams@arm.com>
Change-Id: I4579db7b5959e0a22256f1bda00238c22e611dec
diff --git a/src/backends/reference/workloads/RefConcatWorkload.cpp b/src/backends/reference/workloads/RefConcatWorkload.cpp
index e606649..c04c053 100644
--- a/src/backends/reference/workloads/RefConcatWorkload.cpp
+++ b/src/backends/reference/workloads/RefConcatWorkload.cpp
@@ -14,8 +14,18 @@
 
 void RefConcatWorkload::Execute() const
 {
+    Execute(m_Data.m_Inputs, m_Data.m_Outputs);
+}
+
+void RefConcatWorkload::ExecuteAsync(WorkingMemDescriptor &workingMemDescriptor)
+{
+    Execute(workingMemDescriptor.m_Inputs, workingMemDescriptor.m_Outputs);
+}
+
+void RefConcatWorkload::Execute(std::vector<ITensorHandle*> inputs, std::vector<ITensorHandle*> outputs) const
+{
     ARMNN_SCOPED_PROFILING_EVENT(Compute::CpuRef, "RefConcatWorkload_Execute");
-    Concatenate(m_Data);
+    Concatenate(m_Data, inputs, outputs);
 }
 
 } //namespace armnn