maxwell_3d: Implement a safer CB data upload

This makes constant buffer uploads safer and more accurate by updating the GPU memory as soon as the CB Data method is invoked. The previous implementation was deferring the updates until a different maxwell 3d method was detected, then writing all CB data at once.

src/video_core/engines/maxwell_3d.h

@@ -1520,10 +1520,8 @@ private:
     void ProcessSyncPoint();
 
     /// Handles a write to the CB_DATA[i] register.
-    void StartCBData(u32 method);
     void ProcessCBData(u32 value);
-    void ProcessCBMultiData(u32 method, const u32* start_base, u32 amount);
-    void FinishCBData();
+    void ProcessCBMultiData(const u32* start_base, u32 amount);
 
     /// Handles a write to the CB_BIND register.
     void ProcessCBBind(size_t stage_index);
@@ -1555,17 +1553,6 @@ private:
     /// Interpreter for the macro codes uploaded to the GPU.
     std::unique_ptr<MacroEngine> macro_engine;
 
-    static constexpr u32 null_cb_data = 0xFFFFFFFF;
-    struct CBDataState {
-        static constexpr size_t inline_size = 0x4000;
-        std::array<std::array<u32, inline_size>, 16> buffer;
-        u32 current{null_cb_data};
-        u32 id{null_cb_data};
-        u32 start_pos{};
-        u32 counter{};
-    };
-    CBDataState cb_data_state;
-
     Upload::State upload_state;
 
     bool execute_on{true};