add build system modules

Author: HeartLinked

LICENSE

@@ -214,9 +214,13 @@ License: Public Domain
 
 This product includes code from Apache Arrow.
 
-* checked_cast utility in src/iceberg/util/checked_cast.h.
-* visit_type utility in src/iceberg/util/visit_type.h.
-* Decimal128 implementation details in src/iceberg/util/decimal files.
+* Core utilities:
+  * checked_cast utility in src/iceberg/util/checked_cast.h.
+  * visit_type utility in src/iceberg/util/visit_type.h.
+  * Decimal128 implementation details in src/iceberg/util/decimal files.
+* Build system modules:
+  * cmake_modules/IcebergBuildUtils.cmake.
+  * cmake_modules/IcebergThirdpartyToolchain.cmake.
 
 Copyright: 2016-2025 The Apache Software Foundation.
 Home page: https://arrow.apache.org/