hg: shenandoah/jdk8/hotspot: Avoid initializing unused SharedHeap::_workers for Shenandoah

[shade at redhat.com]

Changeset: dae45258de89
Author:    shade
Date:      2019-10-25 10:23 +0200
URL:       https://hg.openjdk.java.net/shenandoah/jdk8/hotspot/rev/dae45258de89

Avoid initializing unused SharedHeap::_workers for Shenandoah

! src/share/vm/gc_implementation/shenandoah/shenandoahHeap.cpp
! src/share/vm/gc_implementation/shenandoah/shenandoahHeap.hpp
! src/share/vm/gc_implementation/shenandoah/shenandoahHeap.inline.hpp
! src/share/vm/memory/sharedHeap.cpp