IVGCVSW-2092 Port LSTMCell::Eval to ArmNN

 * Ported Google's LSTM implementation to RefLstmFloat32Workload
 * Fixed the code throughout because of an error in the docs around the
   scratch buffer size
 * Updated IsLstmSupported
 * Added the unit tests

!android-nn-driver:127

Change-Id: I5577b7e39ca52df1a7f102a9b437df6aa99520b6
diff --git a/src/backends/reference/workloads/RefLstmFloat32Workload.hpp b/src/backends/reference/workloads/RefLstmFloat32Workload.hpp
index 1f634d3..a2dead8 100644
--- a/src/backends/reference/workloads/RefLstmFloat32Workload.hpp
+++ b/src/backends/reference/workloads/RefLstmFloat32Workload.hpp
@@ -5,6 +5,8 @@
 
 #pragma once
 
+#include <armnn/TypesUtils.hpp>
+
 #include <backendsCommon/Workload.hpp>
 #include <backendsCommon/WorkloadData.hpp>
 
@@ -14,8 +16,28 @@
 class RefLstmFloat32Workload : public Float32Workload<LstmQueueDescriptor>
 {
 public:
-    using Float32Workload<LstmQueueDescriptor>::Float32Workload;
+    explicit RefLstmFloat32Workload(const LstmQueueDescriptor& descriptor, const WorkloadInfo& info);
+
     virtual void Execute() const override;
+
+private:
+    std::unique_ptr<ScopedCpuTensorHandle> m_InputToInputWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_InputToForgetWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_InputToCellWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_InputToOutputWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_RecurrentToInputWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_RecurrentToForgetWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_RecurrentToCellWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_RecurrentToOutputWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_CellToInputWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_CellToForgetWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_CellToOutputWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_InputGateBiasTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_ForgetGateBiasTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_CellBiasTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_OutputGateBiasTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_ProjectionWeightsTensor;
+    std::unique_ptr<ScopedCpuTensorHandle> m_ProjectionBiasTensor;
 };
 
 } //namespace armnn