RFR(xs): 8224487: outputStream should not be copyable

[Thomas Stüfe]

Hi all,
may I please have a review for this small fix. With JDK-8224193 (not yet
pushed) I saw a number of crashes which were caused by code handing around
copies of outputStream objects but copy semantics are not implemented.

This fix forbids copying for outputStream and its descendants and fixes the
few places where that happened.

Bug: https://bugs.openjdk.java.net/browse/JDK-8224487
cr:
http://cr.openjdk.java.net/~stuefe/webrevs/8224487-make-streams-not-copyable/webrev.00/webrev/

Note: In event log coding, I removed the convenience function stringStream
FormatStringLogMessage::stream(). This makes the (very few) call sites
slightly more verbose but I have open for RFR a cleanup of the event log
system (see JDK-8220762,
https://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2019-May/034349.html)
which will simplify and cleanup this coding anyway.

Thank you,

Thomas