HLSL: Add CalculateLevelOfDetail, and unimplemented errors for *Unclamped and GetSamplePosition

Test/hlsl.getsampleposition.dx10.frag

@@ -0,0 +1,23 @@
+SamplerState       g_sSamp : register(s0);
+
+Texture2DMS      <float4>  g_tTex2dmsf4;
+Texture2DMSArray <float4>  g_tTex2dmsf4a;
+
+struct PS_OUTPUT
+{
+    float4 Color : SV_Target0;
+    float  Depth : SV_Depth;
+};
+
+PS_OUTPUT main()
+{
+   PS_OUTPUT psout;
+
+   float2 r00 = g_tTex2dmsf4.GetSamplePosition(1);
+   float2 r01 = g_tTex2dmsf4a.GetSamplePosition(2);
+
+   psout.Color = 1.0;
+   psout.Depth = 1.0;
+
+   return psout;
+}