I do think ggtags is doing something weird here. But on the other hand,
it does seem better if `save-some-buffers' required `buffer-offer-save'
to be explicitly set non-nil, rather than drawing an implicit conclusion
from the presence of `write-contents-functions'.

Ie maybe I should just revert the change to this function, and make sure
to set `buffer-offer-save' to t in my use-case. No one will get
surprised by save prompts they didn't ask for. That way I could also
remove the buffer name check.

WDYT?