Unscale textureSize when resolution scaling is used (#2441)

* Unscale textureSize when resolution scaling is used

* Fix textureSize on compute

* Flag texture size as needing res scale values too

Ryujinx.Graphics.Shader/CodeGen/Glsl/HelperFunctions/TexelFetchScale_fp.glsl

@@ -13,4 +13,14 @@
     {
         return ivec2(vec2(inputVec) * scale);
     }
+}
+
+int Helper_TextureSizeUnscale(int size, int samplerIndex)
+{
+    float scale = abs(fp_renderScale[1 + samplerIndex]);
+    if (scale == 1.0)
+    {
+        return size;
+    }
+    return int(float(size) / scale);
 }