Fixed json null value parsing

core/encoding/json/marshal.odin

@@ -176,7 +176,13 @@ marshal_to_writer :: proc(w: io.Writer, v: any, opt: ^Marshal_Options) -> (err:
 		return .Unsupported_Type
 
 	case runtime.Type_Info_Pointer:
-		return .Unsupported_Type
+		ptr := a.(rawptr)
+
+		if ptr == nil {
+			io.write_string(w, "null") or_return
+		} else {
+			return .Unsupported_Type
+		}
 
 	case runtime.Type_Info_Multi_Pointer:
 		return .Unsupported_Type