8183536: Update jdk tests to allow for unique test classes directory

[Alan Bateman]

jtreg has been updated via CODETOOLS-7902003 [1] to use a unique 
test.classes directory. This is part of improving the reliability when 
running tests concurrently. The change exposes issues in a tiny number 
of tests that use test.classes in odd ways. For the jdk repo then two 
tests need to be updated. There are a few others in the hotspot [2] and 
langtools [3] repos that also need to be fixed before the jtreg 
requiredVersion can be bumped to use a promoted jtreg with the change.

While in the area, I also changed a number of recent tests to not use 
the temporary file system. Tim Bell has created a lot of bugs on this 
recently, I think because he observed /tmp filling up.

The (trivial) patch with the updates to the tests is here:
   http://cr.openjdk.java.net/~alanb/8183536/webrev/index.html

I'd like to get this into jdk10/jdk10 to meet up with the test updates 
in the other repos.

-Alan.

[1] https://bugs.openjdk.java.net/browse/CODETOOLS-7902003
[2] 
http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2017-July/023841.html
[3] 
http://mail.openjdk.java.net/pipermail/compiler-dev/2017-July/011012.html