[D3D12] ROV: Check if supported

src/xenia/gpu/d3d12/pipeline_cache.h

@@ -35,7 +35,7 @@ class PipelineCache {
   };
 
   PipelineCache(D3D12CommandProcessor* command_processor,
-                RegisterFile* register_file);
+                RegisterFile* register_file, bool edram_rov_used);
   ~PipelineCache();
 
   void Shutdown();
@@ -85,6 +85,9 @@ class PipelineCache {
   D3D12CommandProcessor* command_processor_;
   RegisterFile* register_file_;
 
+  // Whether the output merger is emulated in pixel shaders.
+  bool edram_rov_used_;
+
   // Reusable shader translator.
   std::unique_ptr<DxbcShaderTranslator> shader_translator_ = nullptr;
   // All loaded shaders mapped by their guest hash key.