RFR (XS) 8212609: Minimal VM build failure after JDK-8210498 (nmethod entry barriers)

[Aleksey Shipilev]

Bug:
  https://bugs.openjdk.java.net/browse/JDK-8212609

Fix:

diff -r cba34f27d9ce src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp
--- a/src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp      Wed Oct 17 22:06:55 2018 +0800
+++ b/src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp      Wed Oct 17 17:42:14 2018 +0200
@@ -34,6 +34,8 @@
 #include "code/vtableStubs.hpp"
 #include "gc/shared/collectedHeap.hpp"
 #include "gc/shared/gcLocker.hpp"
+#include "gc/shared/barrierSet.hpp"
+#include "gc/shared/barrierSetAssembler.hpp"
 #include "interpreter/interpreter.hpp"
 #include "logging/log.hpp"
 #include "memory/resourceArea.hpp"


I contemplated ifdef-ing the actual call to BSAsm here:

  BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
  bs->nmethod_entry_barrier(masm);

...but thought it is cleaner to let barrier BSAsm figure out whatever compiler-specific thing needs
to be done.

Testing: x86_64-minimal builds

Thanks,
-Aleksey