RFA/RFR [10] 8202540: Zero build is broken after JDK-8189871 (Refactor GC barriers to use declarative semantics)

[Aleksey Shipilev]

This is a bit unconventional process-wise, because there is a fix in JDK 11, but it comes with the
bunch of other unrelated changes that are not backportable to 10u. So, I opted to submit a separate
bug for this. I added the jdk10u-fix-request tag and appropriate comment.

10u bug:
  https://bugs.openjdk.java.net/browse/JDK-8202540

11 bug:
 https://bugs.openjdk.java.net/browse/JDK-8199220

10u fix:

diff -r e4530ef14c08 src/hotspot/cpu/zero/globalDefinitions_zero.hpp
--- a/src/hotspot/cpu/zero/globalDefinitions_zero.hpp	Wed Mar 28 14:24:17 2018 +0100
+++ b/src/hotspot/cpu/zero/globalDefinitions_zero.hpp	Wed May 02 12:03:18 2018 +0200
@@ -26,6 +26,10 @@
 #ifndef CPU_ZERO_VM_GLOBALDEFINITIONS_ZERO_HPP
 #define CPU_ZERO_VM_GLOBALDEFINITIONS_ZERO_HPP

+#ifdef _LP64
+#define SUPPORTS_NATIVE_CX8
+#endif
+
 #include <ffi.h>

 // Indicates whether the C calling conventions require that

Testing: x86_64 Zero builds

Thanks,
-Aleksey