Fix compiler warnings.

com.unity.render-pipelines.core/CoreRP/Editor/TextureCombiner/TextureCombiner.cs

             return tex;
     }
 
-    public static TextureFormat[] TextureFormatsWithouthAlpha = new TextureFormat[] {
+    private static TextureFormat[] TextureFormatsWithouthAlpha = {
         TextureFormat.ASTC_RGB_10x10 ,
         TextureFormat.ASTC_RGB_12x12 ,
         TextureFormat.ASTC_RGB_4x4 ,
         TextureFormat.EAC_RG_SIGNED ,
         TextureFormat.ETC2_RGB ,
         TextureFormat.ETC_RGB4 ,
+        #if !UNITY_2018_3_OR_NEWER
+        #endif
         TextureFormat.ETC_RGB4Crunched ,
         TextureFormat.PVRTC_RGB2 ,
         TextureFormat.PVRTC_RGB4 ,
     private int m_aChanel;
 
     // Chanels remaping
-    private Vector4[] m_remapings = new Vector4[] {
+    private Vector4[] m_remapings = {
         new Vector4(0f, 1f, 0f, 0f),
         new Vector4(0f, 1f, 0f, 0f),
         new Vector4(0f, 1f, 0f, 0f),

com.unity.render-pipelines.lightweight/LWRP/Editor/ShaderGraph/LightWeightPBRSubShader.cs

     [FormerName("UnityEditor.ShaderGraph.LightWeightPBRSubShader")]
     public class LightWeightPBRSubShader : IPBRSubShader
     {
-        static NeededCoordinateSpace m_VertexCoordinateSpace = NeededCoordinateSpace.Object;
         static NeededCoordinateSpace m_PixelCoordinateSpace = NeededCoordinateSpace.World;
 
         struct Pass

com.unity.render-pipelines.lightweight/LWRP/Editor/ShaderGraph/LightWeightUnlitSubShader.cs

     [FormerName("UnityEditor.ShaderGraph.LightWeightUnlitSubShader")]
     public class LightWeightUnlitSubShader : IUnlitSubShader
     {
-        static NeededCoordinateSpace m_VertexCoordinateSpace = NeededCoordinateSpace.Object;
         static NeededCoordinateSpace m_PixelCoordinateSpace = NeededCoordinateSpace.World;
 
         struct Pass