RFR(S) 8204521: compiler/jsr292/RedefineMethodUsedByMultipleMethodHandles.java fails trying to delete temp file

[dean.long at oracle.com]

https://bugs.openjdk.java.net/browse/JDK-8204521
http://cr.openjdk.java.net/~dlong/8204521/webrev/

Agent jar files are added to the system classloader, so it is not safe 
to delete them while the JVM is running.  Instead we create the jar file 
in the test directory so that it can be cleaned up by the test harness.

dl