More descriptive exclusion error; updated docs and copyright

build/single_file_libs/zstd-in.c

@@ -4,11 +4,11 @@
  *
  * Generate using:
  * \code
- *	combine.sh -r ../../lib -x legacy/zstd_legacy.h -o zstd.c zstd-in.c
+ *	python combine.py -r ../../lib -x legacy/zstd_legacy.h -o zstd.c zstd-in.c
  * \endcode
  */
 /*
- * Copyright (c) 2016-2021, Yann Collet, Facebook, Inc.
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
@@ -28,6 +28,10 @@
  * Note: the undefs for xxHash allow Zstd's implementation to coincide with with
  * standalone xxHash usage (with global defines).
  *
+ * Note: if you enable ZSTD_LEGACY_SUPPORT the combine.py script will need
+ * re-running without the "-x legacy/zstd_legacy.h" option (it excludes the
+ * legacy support at the source level).
+ *
  * Note: multithreading is enabled for all platforms apart from Emscripten.
  */
 #define DEBUGLEVEL 0