D3D: Reduce the number of DirectX API calls. However, it does not seem to give tiny speed up. If anyone find that this change actually slows DX9 down, I will revert it.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@4237 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Plugins/Plugin_VideoDX9/Src/PixelShaderCache.h

@@ -51,6 +51,7 @@ private:
 
 	static PSCache PixelShaders;
 	static const PSCacheEntry *last_entry;
+	static PIXELSHADERUID last_entry_uid;
 
 public:
 	static void Init();