hg: code-tools/jtreg: 7902199: some of jtreg's tests require update for macOS

[jonathan.gibbons at oracle.com]

Changeset: cb916d8339f8
Author:    jjg
Date:      2018-07-02 17:10 -0700
URL:       http://hg.openjdk.java.net/code-tools/jtreg/rev/cb916d8339f8

7902199: some of jtreg's tests require update for macOS
Contributed-by: igor.ignatyev at oracle.com

! make/Platform.gmk
! test/6517916/T6517916.gmk
! test/classIsolation/ClassIsolationTest.gmk
! test/debug/DebugTest.gmk