[D3D12] Make trace dump partially work

src/xenia/gpu/null/null_command_processor.cc

@@ -18,6 +18,9 @@ NullCommandProcessor::NullCommandProcessor(NullGraphicsSystem* graphics_system,
     : CommandProcessor(graphics_system, kernel_state) {}
 NullCommandProcessor::~NullCommandProcessor() = default;
 
+void NullCommandProcessor::TracePlaybackWroteMemory(uint32_t base_ptr,
+                                                    uint32_t length) {}
+
 bool NullCommandProcessor::SetupContext() {
   return CommandProcessor::SetupContext();
 }

src/xenia/gpu/null/null_command_processor.h

@@ -25,6 +25,8 @@ class NullCommandProcessor : public CommandProcessor {
                        kernel::KernelState* kernel_state);
   ~NullCommandProcessor();
 
+  void TracePlaybackWroteMemory(uint32_t base_ptr, uint32_t length) override;
+
  private:
   bool SetupContext() override;
   void ShutdownContext() override;