RFR: 8154759: [TESTBUG] GC tests should be changed to be able to execute with -Xlog:all=trace.

[Michail Chernov]

Hi,

Could I have a reviews for this small change please.

https://bugs.openjdk.java.net/browse/JDK-8154759
http://cr.openjdk.java.net/~mchernov/8154759/webrev.00/

Tests now filter out -Xlog* option. This is needed because we are going 
to extend GC nightly by adding -Xlog:all=trace to default GC baseline to 
check unified gc logging (https://bugs.openjdk.java.net/browse/JDK-8150845).

Thanks
Michail