IVGCVSW-3546 Create a reference dynamic backend to use for testing and as
an example in the docs

 * Wrapped the reference backend into a dynamic backend
 * Moved the static registration code to a separate file, so that
   it is possible to create the reference dynamic backend that does not
   register statically into armnn
 * Added unit test

Change-Id: I1074d21b020820f9ac8c7178388be773b447555a
Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>
diff --git a/src/backends/backendsCommon/BackendRegistry.cpp b/src/backends/backendsCommon/BackendRegistry.cpp
index 80ab01c..7078304 100644
--- a/src/backends/backendsCommon/BackendRegistry.cpp
+++ b/src/backends/backendsCommon/BackendRegistry.cpp
@@ -17,7 +17,7 @@
 
 void BackendRegistry::Register(const BackendId& id, BackendRegistry::FactoryFunction factory)
 {
-    if (m_Factories.count(id) > 0)
+    if (m_Factories.find(id) != m_Factories.end())
     {
         throw InvalidArgumentException(
             std::string(id) + " already registered as IBackend factory",