RFR: 8150823: UL handles disabling logs incorrectly

[Marcus Larsson]

Hi,

Please review the following patch to fix a problem with disabling log 
outputs using -Xlog:disable or disable_logging() when there are multiple 
file outputs configured. The patch also resolves an issue with log file 
lookups that could cause multiple outputs to be created for the same log 
file.

Log output removal now iterates backwards to not invalidate the loop 
index, and file outputs are always prepended with "file=" during lookups 
and listings.

Webrev:
http://cr.openjdk.java.net/~mlarsson/8150823/webrev.00/

Issue:
https://bugs.openjdk.java.net/browse/JDK-8150823

Testing:
Included tests through RBT

Thanks,
Marcus