RFR 8170044: jshell tool: jshell missing from javax.tools.ToolProvider

[Robert Field]

Bug:

    https://bugs.openjdk.java.net/browse/JDK-8170044 <https://bugs.openjdk.java.net/browse/JDK-8170044>

Webrev:

    http://cr.openjdk.java.net/~rfield/8170044v0.webrev/ <http://cr.openjdk.java.net/~rfield/8170044v0.webrev/>

Thanks,
Robert