lib/Tools/scalac

clarified output;

#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: invoke Scala compiler within the Isabelle environment

isabelle scala_build || exit $?

classpath "$ISABELLE_SETUP_CLASSPATH"; unset ISABELLE_SETUP_CLASSPATH
classpath "$CLASSPATH"; export CLASSPATH=""

isabelle_scala scalac -Dfile.encoding=UTF-8 \
  -classpath "$(platform_path "$ISABELLE_CLASSPATH")" "$@"