Give unique names to debug layers

Debug layers are given names based on the layer they take their input from.
If a layer has multiple outputs then one debug layer will be attached to
each output. Therefore all these debug layers would have identical names
making them hard to distinguish when debugging. This patch includes the
output slot index which the debug layer takes its input from when creating
the name.

Change-Id: I09eaa8a7edad9bfdf678b4778cf740340013126c
Signed-off-by: Rob Hughes <robert.hughes@arm.com>
diff --git a/src/backends/reference/test/RefOptimizedNetworkTests.cpp b/src/backends/reference/test/RefOptimizedNetworkTests.cpp
index 086c1e4..2f25b6c 100644
--- a/src/backends/reference/test/RefOptimizedNetworkTests.cpp
+++ b/src/backends/reference/test/RefOptimizedNetworkTests.cpp
@@ -196,9 +196,9 @@
 
     // Tests that the vertices exist and have correct names.
     BOOST_TEST(GraphHasNamedLayer(graph, "InputLayer"));
-    BOOST_TEST(GraphHasNamedLayer(graph, "DebugLayerAfterInputLayer"));
+    BOOST_TEST(GraphHasNamedLayer(graph, "DebugLayerAfterInputLayer_0"));
     BOOST_TEST(GraphHasNamedLayer(graph, "ActivationLayer"));
-    BOOST_TEST(GraphHasNamedLayer(graph, "DebugLayerAfterActivationLayer"));
+    BOOST_TEST(GraphHasNamedLayer(graph, "DebugLayerAfterActivationLayer_0"));
     BOOST_TEST(GraphHasNamedLayer(graph, "OutputLayer"));
 }