[SYCL] Check for duplicates in handler::addAccessorReq()

Constructor of accessors add them to MRequirements and MAccStorage
of the associated handler, so do not add duplicates here if same
handler was used during construction.

Author: Alexandr-Konovalov

sycl/source/handler.cpp

@@ -2056,6 +2056,14 @@ void handler::SetHostTask(std::function<void(interop_handle)> &&Func) {
 }
 
 void handler::addAccessorReq(detail::AccessorImplPtr Accessor) {
+  // Constructor of accessors add them to MRequirements and MAccStorage
+  // of the associated handler, so do not add duplicates if use same
+  // handler as during construction.
+  if (impl->CGData.MRequirements.end() !=
+      std::find(impl->CGData.MRequirements.begin(),
+                impl->CGData.MRequirements.end(), Accessor.get()))
+    return;
+
   // Add accessor to the list of requirements.
   impl->CGData.MRequirements.push_back(Accessor.get());
   // Store copy of the accessor.