scripts: Add git-resolve tool for full SHA-1 resolution

scripts: Add git-resolve tool for full SHA-1 resolution

Introduce git-resolve.sh, a tool that resolves short git commit IDs to their
full SHA-1 hash. This is particularly useful for navigating references in commit
messages and verifying Fixes tags.

When faced with ambiguous commit IDs or imprecise references in messages,
this tool can help by resolving commit hashes based on not just the ID
itself but also the commit subject, making it more robust than standard
git rev-parse.

This is especially valuable for maintainers who need to verify Fixes tags
or cross-reference commits. Unlike proposals to add dates to Fixes tags
(which would break existing tooling), this script provides a way to
disambiguate commits without changing the established tag format.

The script includes several features:
- Resolves short commit IDs to full SHA-1 hashes
- Uses commit subjects to disambiguate between multiple potential matches
- Supports wildcard patterns in subjects with ellipsis (...)
- Provides a force mode to attempt resolution by subject when ID lookup fails
- Includes comprehensive self-tests

Signed-off-by: Sasha Levin <sashal@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250311165336.248120-1-sashal@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>