comint-kill-region is an interactive compiled Lisp function in `comint.el'.

(comint-kill-region BEG END)

Like `kill-region', but ignores read-only properties, if safe.
This command assumes that the buffer contains read-only
"prompts" which are regions with front-sticky read-only
properties at the beginning of a line, with the preceding newline
being read-only to protect the prompt. This is true of the
comint prompts if `comint-prompt-read-only' is non-nil. This
command will not delete the region if this would create mutilated
or out of place prompts. That is, if any part of a prompt is
deleted, the entire prompt must be deleted and all remaining
prompts should stay at the beginning of a line. If this is not
the case, this command just calls `kill-region' with all
read-only properties intact. The read-only status of newlines is
updated using `comint-update-fence', if necessary.