JDK-8187977 broke the build for Zero VM.

In file included from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/memory/allocation.inline.hpp:28:0,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/oops/array.hpp:29,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/memory/universe.hpp:28,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/code/oopRecorder.hpp:28,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/asm/codeBuffer.hpp:28,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/asm/assembler.hpp:28,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/precompiled/precompiled.hpp:29:
/home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/runtime/atomic.hpp: In instantiation of 'static D Atomic::xchg(T, volatile D*) [with T = unsigned int; D = int]':
/home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/prims/jni.cpp:3901:41: required from here
/home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/runtime/atomic.hpp:914:47: error: invalid use of incomplete type 'struct Atomic::XchgImpl<unsigned int, int, void>'
   return XchgImpl<T, D>()(exchange_value, dest);
                                               ^
In file included from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/memory/allocation.inline.hpp:28:0,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/oops/array.hpp:29,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/memory/universe.hpp:28,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/code/oopRecorder.hpp:28,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/asm/codeBuffer.hpp:28,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/asm/assembler.hpp:28,
                 from /home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/precompiled/precompiled.hpp:29:
/home/rkennke/src/openjdk/jdk10-hs-single/src/hotspot/share/runtime/atomic.hpp:352:10: error: declaration of 'struct Atomic::XchgImpl<unsigned int, int, void>'
   struct XchgImpl;
          ^
gmake[3]: *** [/home/rkennke/src/openjdk/jdk10-hs-single/build/linux-x86_64-normal-zero-slowdebug/hotspot/variant-zero/libjvm/objs/jni.o] Error 1