update local copies of HLSLSupport and UnityStandardCore to match changes in Unity src tree and fix errors after updating

Assets/ScriptableRenderPipeline/MobileRenderPipeline/ClassicDeferred/HLSLSupport.cginc

 #define SV_POSITION POSITION
 #endif
 
+// Declare position that is also available for read in fragment shader
+#if defined(SHADER_API_D3D9) && defined(SHADER_STAGE_FRAGMENT) && SHADER_TARGET >= 30
+#define UNITY_POSITION(pos) float4 pos : VPOS
+#else
+// On D3D reading screen space coordinates from fragment shader requires SM3.0
+#define UNITY_POSITION(pos) float4 pos : SV_POSITION
+#endif
 
 #if defined(SHADER_API_D3D9) || defined(SHADER_API_D3D11) || defined(SHADER_API_D3D11_9X) || defined(SHADER_API_PSP2) || defined(SHADER_API_PSSL)
 #define UNITY_ATTEN_CHANNEL r

Assets/ScriptableRenderPipeline/MobileRenderPipeline/ClassicDeferred/UnityStandardCore.cginc

 
 struct VertexOutputForwardBase
 {
-	float4 pos							: SV_POSITION;
+	UNITY_POSITION(pos);
 	float4 tex							: TEXCOORD0;
 	half3 eyeVec 						: TEXCOORD1;
 	half4 tangentToWorldAndPackedData[3]	: TEXCOORD2;	// [3x3:tangentToWorld | 1x3:viewDirForParallax or worldPos]
 
 struct VertexOutputForwardAdd
 {
-	float4 pos							: SV_POSITION;
+	UNITY_POSITION(pos);
 	float4 tex							: TEXCOORD0;
 	half3 eyeVec 						: TEXCOORD1;
 	half4 tangentToWorldAndLightDir[3]	: TEXCOORD2;	// [3x3:tangentToWorld | 1x3:lightDir]
 
 struct VertexOutputDeferred
 {
-	float4 pos							: SV_POSITION;
+	UNITY_POSITION(pos);
 	float4 tex							: TEXCOORD0;
 	half3 eyeVec 						: TEXCOORD1;
 	half4 tangentToWorldAndPackedData[3]: TEXCOORD2;	// [3x3:tangentToWorld | 1x3:viewDirForParallax or worldPos]