Missing bazel-diff support for change executable bit of files

[lukasmi93]

I have noticed that the change of an executable bit for a file included in a filegroup is not detected by bazel-diff. This has made it a bit challenging to accurately track certain changes.

The simple change in the SourceFileHasher.kt file can fix this behavior:

val isExecutable =
    try {
            java.nio.file.Files.getPosixFilePermissions(absoluteFilePath).let { perms ->
            perms.contains(java.nio.file.attribute.PosixFilePermission.OWNER_EXECUTE) ||
            perms.contains(java.nio.file.attribute.PosixFilePermission.GROUP_EXECUTE) ||
            perms.contains(java.nio.file.attribute.PosixFilePermission.OTHERS_EXECUTE)
          }
        } catch (_: Exception) {
          // Fallback for non-POSIX filesystems.
          file.canExecute()
        }
putBytes(byteArrayOf(if (isExecutable) 0x01 else 0x00))

I'm curious to know if there are any planned improvements or updates that might address this behavior in the near future.

Thanks in advance for your help!

[tinder-maxwellelliott]

This looks like a great fix, id more than welcome it