hg: shenandoah/jdk: Fix clang build warnings

[shade at redhat.com]

Changeset: 2302522f94c4
Author:    shade
Date:      2018-11-01 15:46 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/2302522f94c4

Fix clang build warnings

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