RFR(S): 8168122: Update logging in perfMemory to Unified Logging

[Rachel Protacio]

Hello,

Please review this enhancement, converting the following two perfMemory 
options to Unified Logging:
-XX:+PerfTraceMemOps to +Xlog:perf+memops=debug
-XX:+PerfTraceDataCreation to +Xlog:perf+datacreation=debug

Functionality verified manually.

JIRA: https://bugs.openjdk.java.net/browse/JDK-8168122
Changeset: http://cr.openjdk.java.net/~rprotacio/8168122.00/

Thanks!
Rachel