it seems that ^X does not exit a breaking point to the main picolisp process anymore.
When I break a process with ^C, for example `(loop (println "hello world") (wait 1000))`, I enter a breakpoint, but I can't return to toplevel with ^X as I used to. was this functionality disabled? for now, I can write `(quit)` in the breakpoint prompt to go to toplevel, though the lack of ^X caught me by surprise.
