nasm/headers/doc

\# SPDX-License-Identifier: BSD-2-Clause
\# Copyright 1996-20xx The NASM Authors - All Rights Reserved
treewide: replace verbose copyright headers with SPDX tags SPDX is an international standard for documenting software license requirements. Remove the existing headers and replace with a brief SPDX preamble. See: https://spdx.dev/use/specifications/ The script used to convert the files is added to "tools", and the file header templates in headers/ are updated. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> 2025-10-01 11:25:38 -07:00			`\# SPDX-License-Identifier: BSD-2-Clause`
Fix more license headers 2025-10-01 12:05:34 -07:00			`\# Copyright 1996-20xx The NASM Authors - All Rights Reserved`