hg: shenandoah/jdk: Filter out heap walk related hotspot_serviceability test

[zgu at redhat.com]

Changeset: 947fd298289b
Author:    zgu
Date:      2018-11-28 16:41 -0500
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/947fd298289b

Filter out heap walk related hotspot_serviceability test

! test/hotspot/jtreg/serviceability/sa/ClhsdbJhisto.java
! test/hotspot/jtreg/serviceability/sa/TestHeapDumpForLargeArray.java