after-insert-file-set-coding is a compiled Lisp function in `
(after-insert-file-set-coding INSERTED &optional VISIT)
Set `buffer-file-coding-system' of current buffer after text is inserted.
INSERTED is the number of characters that were inserted, as figured
in the situation before this function. Return the number of characters
inserted, as figured in the situation after. The two numbers can be
different if the buffer has become unibyte.
The optional second arg VISIT non-nil means that we are visiting a file.