hg: shenandoah/jdk11: Fix clang build warnings

[shade at redhat.com]

Changeset: e0899f18c2c1
Author:    shade
Date:      2018-11-01 15:46 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk11/rev/e0899f18c2c1

Fix clang build warnings

! src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp
! src/hotspot/share/opto/arraycopynode.cpp