RFR: 8154791: Xlog classload too redundant msgs info/debug

[Max Ockner]

Hello,

Please review this small change to logging for class loading.

Webrev: http://cr.openjdk.java.net/~mockner/8154791.02/
Bug: https://bugs.openjdk.java.net/browse/JDK-8154791

-Xlog:class+load=debug used to produce redundant info. Some of the debug 
level lines were nearly identical to some of the info level lines. To 
reduce the redundant information, these debug messages have been moved 
into the info level, replacing the corresponding info messages.

Tested with jtreg runtime.

I can wait to submit this until after the FC deadline.

Thanks,
Max