Match more SVE/SME specific details.
Also lowercase all register names. As this matches many cases
of code comments that refer to variables elsewhere, not specific
registers, we only apply this tranformation on the part of lines
before a potential comment.
This allows using the tool for one-off reindentations without needing
the check_arm_indent.sh script (e.g. for use outside of ffmpeg),
without having to pipe the file through stdin/stdout.
The same also applies for arm assembly, but there are more known
deviations within that.
Add a script which checks all files, except for a few known files
that deviate, for various reasons.
