od: Add support for -tfH and -tfB

[karanabe]

Recognize the fH/fB specifiers, convert 16-bit floats to f64, and format them with the correct field widths to match GNU od.

Fixes #8345

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/timeout/timeout (fails in this run but passes in the 'main' branch)

[karanabe]

CI’s cspell check flagged “bfloat” as a misspelling—may I add “bfloat” to the cspell workspace.wordlist at function names section?

[cakebaker]

Yes, that sounds good. Alternatively, you could also add a spell-checker:ignore entry to the top of the files (many files already have such entries).

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/stdbuf (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)

[karanabe]

Thanks for the suggestion! I’ve added the spell-checker:ignore bfloat entry at the top of the files and CI is now passing.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/timeout/timeout (passes in this run but fails in the 'main' branch)

[karanabe]

There are no real code changes here—I just cleaned up the merge conflicts that occurred on the identical lines.

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)

[RenjiSann]

Thank you for your contribution ! Can you squash your commits to only have 1 (or 2 if you wish to have a specific commit for the tests) ?

This improves the readability of the commit tree in main.

[karanabe]

Thank you for the review! I’ve rebased and squashed my changes into a single commit.

[RenjiSann]

Thank you for your contribution !

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)