Fix compilation of Flax.Build with older C# compiler

Source/Tools/Flax.Build/Bindings/BindingsGenerator.Cache.cs

@@ -42,6 +42,34 @@ namespace Flax.Build.Bindings
             }
         }
 
+        internal static void Write(BinaryWriter writer, HashSet<string> list)
+        {
+            if (list != null)
+            {
+                writer.Write(list.Count());
+                foreach (var e in list)
+                    writer.Write(e);
+            }
+            else
+            {
+                writer.Write(0);
+            }
+        }
+
+        internal static void Write(BinaryWriter writer, List<string> list)
+        {
+            if (list != null)
+            {
+                writer.Write(list.Count());
+                foreach (var e in list)
+                    writer.Write(e);
+            }
+            else
+            {
+                writer.Write(0);
+            }
+        }
+
         internal static void Write(BinaryWriter writer, IEnumerable<string> list)
         {
             if (list != null)
@@ -69,7 +97,7 @@ namespace Flax.Build.Bindings
             }
         }
 
-        internal static void Write<T>(BinaryWriter writer, IList<T> list) where T : IBindingsCache
+        internal static void Write<T>(BinaryWriter writer, List<T> list) where T : IBindingsCache
         {
             if (list != null)
             {
@@ -88,6 +116,25 @@ namespace Flax.Build.Bindings
             }
         }
 
+        internal static void Write<T>(BinaryWriter writer, T[] list) where T : IBindingsCache
+        {
+            if (list != null)
+            {
+                var count = list.Length;
+                writer.Write(count);
+                for (int i = 0; i < count; i++)
+                {
+                    var e = list[i];
+                    writer.Write(e.GetType().FullName);
+                    e.Write(writer);
+                }
+            }
+            else
+            {
+                writer.Write(0);
+            }
+        }
+
         internal static string Read(BinaryReader reader, string e)
         {
             var valid = reader.ReadBoolean();