Added VERTEXID_SEMANTIC to api files. Fixed BlitCubeTextureFace shader on gles 2.0.

ScriptableRenderPipeline/Core/CoreRP/Resources/BlitCubeTextureFace.shader

             Cull Off
 
             HLSLPROGRAM
+            #pragma prefer_hlslcc gles
             #include "CoreRP/ShaderLibrary/Common.hlsl"
 
             #pragma vertex vert
 
             struct Attributes
             {
-                uint vertexID : SV_VertexID;
+                uint vertexID : VERTEXID_SEMANTIC;
             };
 
             struct Varyings

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/API/D3D11.hlsl

 #define UNITY_NEAR_CLIP_VALUE (1.0)
 // This value will not go through any matrix projection conversion
 #define UNITY_RAW_FAR_CLIP_VALUE (0.0)
+#define VERTEXID_SEMANTIC SV_VertexID
 #define FRONT_FACE_SEMANTIC SV_IsFrontFace
 #define FRONT_FACE_TYPE bool
 #define IS_FRONT_VFACE(VAL, FRONT, BACK) ((VAL) ? (FRONT) : (BACK))

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/API/GLCore.hlsl

 
 // This value will not go through any matrix projection convertion
 #define UNITY_RAW_FAR_CLIP_VALUE (1.0)
+#define VERTEXID_SEMANTIC SV_VertexID
 #define FRONT_FACE_SEMANTIC VFACE
 #define FRONT_FACE_TYPE float
 #define IS_FRONT_VFACE(VAL, FRONT, BACK) ((VAL > 0.0) ? (FRONT) : (BACK))

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/API/GLES2.hlsl

 
 // This value will not go through any matrix projection convertion
 #define UNITY_RAW_FAR_CLIP_VALUE (1.0)
+#define VERTEXID_SEMANTIC gl_VertexID
 #define FRONT_FACE_SEMANTIC VFACE
 #define FRONT_FACE_TYPE float
 #define IS_FRONT_VFACE(VAL, FRONT, BACK) ((VAL > 0.0) ? (FRONT) : (BACK))

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/API/GLES3.hlsl

 
 // This value will not go through any matrix projection convertion
 #define UNITY_RAW_FAR_CLIP_VALUE (1.0)
+#define VERTEXID_SEMANTIC SV_VertexID
 #define FRONT_FACE_SEMANTIC VFACE
 #define FRONT_FACE_TYPE float
 #define IS_FRONT_VFACE(VAL, FRONT, BACK) ((VAL > 0.0) ? (FRONT) : (BACK))

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/API/Metal.hlsl

 #define UNITY_NEAR_CLIP_VALUE (1.0)
 // This value will not go through any matrix projection conversion
 #define UNITY_RAW_FAR_CLIP_VALUE (0.0)
+#define VERTEXID_SEMANTIC SV_VertexID
 #define FRONT_FACE_SEMANTIC SV_IsFrontFace
 #define FRONT_FACE_TYPE bool
 #define IS_FRONT_VFACE(VAL, FRONT, BACK) ((VAL) ? (FRONT) : (BACK))

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/API/PSSL.hlsl

 #define UNITY_NEAR_CLIP_VALUE (1.0)
 // This value will not go through any matrix projection convertion
 #define UNITY_RAW_FAR_CLIP_VALUE (0.0)
+#define VERTEXID_SEMANTIC SV_VertexID
 #define FRONT_FACE_SEMANTIC SV_IsFrontFace
 #define FRONT_FACE_TYPE bool
 #define IS_FRONT_VFACE(VAL, FRONT, BACK) ((VAL) ? (FRONT) : (BACK))

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/API/Vulkan.hlsl

 #define UNITY_NEAR_CLIP_VALUE (1.0)
 // This value will not go through any matrix projection conversion
 #define UNITY_RAW_FAR_CLIP_VALUE (0.0)
+#define VERTEXID_SEMANTIC SV_VertexID
 #define FRONT_FACE_SEMANTIC SV_IsFrontFace
 #define FRONT_FACE_TYPE bool
 #define IS_FRONT_VFACE(VAL, FRONT, BACK) ((VAL) ? (FRONT) : (BACK))

ScriptableRenderPipeline/Core/CoreRP/ShaderLibrary/API/XBoxOne.hlsl

 #define UNITY_NEAR_CLIP_VALUE (1.0)
 // This value will not go through any matrix projection conversion
 #define UNITY_RAW_FAR_CLIP_VALUE (0.0)
+#define VERTEXID_SEMANTIC SV_VertexID
 #define FRONT_FACE_SEMANTIC SV_IsFrontFace
 #define FRONT_FACE_TYPE bool
 #define IS_FRONT_VFACE(VAL, FRONT, BACK) ((VAL) ? (FRONT) : (BACK))

ScriptableRenderPipeline/Core/CoreRP/Shadow/Resources/DebugDisplayShadowMap.shader

 
         struct Attributes
         {
-            uint vertexID : SV_VertexID;
+            uint vertexID : VERTEXID_SEMANTIC;
         };
 
         struct Varyings