Adds CustomAllocator interface and Sample App

 * Updates the runtime options with a CustomAllocatorMap which allows to define a CustomAllocator for specific backends
 * Change IBackendInternal interface to use a shared pointer to a custom allocator
 * Update ClBackend.hpp/cpp to use the CustomAllocator
 * Adds an example application and unit test which uses a CustomAllocator for GpuAcc
 * Refactor of the interface to use MemorySource instead of the user Mapping cl_mem directly
 * Modify the BackendRegistry to also hold a registry of CustomAllocators
 * BackendRegistry Deregister will also deregister any allocators associated with that backend id
 * set_global_allocator within the BaseMemoryManager so that it always matches the currently used allocator

Signed-off-by: Jan Eilers <jan.eilers@arm.com>
Change-Id: I156d819686021865f4375e6cb7a5c5dec8fee9e8
Signed-off-by: David Monahan <david.monahan@arm.com>
diff --git a/samples/CMakeLists.txt b/samples/CMakeLists.txt
index ff45eec..7be6a69 100644
--- a/samples/CMakeLists.txt
+++ b/samples/CMakeLists.txt
@@ -8,3 +8,8 @@
     target_link_libraries(DynamicSample armnn ${CMAKE_THREAD_LIBS_INIT})
 endif()
 
+if(BUILD_SAMPLE_APP AND ARMCOMPUTECL)
+    add_executable(CustomMemoryAllocatorSample CustomMemoryAllocatorSample.cpp)
+    target_link_libraries(CustomMemoryAllocatorSample armnn ${CMAKE_THREAD_LIBS_INIT})
+endif()
+