handling overflow in the fixnum*fixnum case of sexp_mul, which is never reached directly from the vm
handling overflow in the fixnum*fixnum case of sexp_mul, which is never reached directly from the vm

holmescn/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme