error when using no_mangle on language items

add suggestion on how to add a panic breakpoint

Co-authored-by: Pat Pannuto <pat.pannuto@gmail.com>
delete no_mangle from ui/panic-handler/panic-handler-wrong-location test

issue an error for the usage of #[no_mangle] on internal language items

delete the comments

add newline

rephrase note

Co-authored-by: bjorn3 <17426603+bjorn3@users.noreply.github.com>
update error not to leak implementation details

delete no_mangle_span

Co-authored-by: bjorn3 <17426603+bjorn3@users.noreply.github.com>
delete commented code