RFR [11]: Fix PCH build failure

[Aleksey Shipilev]

There appears to be a weird header dependency issue somewhere in sh/jdk11.

In file included from
/home/jenkins/workspace/nightly/shenandoah-jdk11/src/hotspot/share/compiler/compileBroker.cpp:72:0:
/home/jenkins/workspace/nightly/shenandoah-jdk11/src/hotspot/share/jvmci/jvmciJavaClasses.hpp:260:15:
error: using typedef-name ‘Value’ after ‘class’
   start_class(Value)                                                                       \
               ^
/home/jenkins/workspace/nightly/shenandoah-jdk11/src/hotspot/share/jvmci/jvmciJavaClasses.hpp:320:7:
note: in definition of macro ‘START_CLASS’
 class name : AllStatic {                                                                   \
       ^
/home/jenkins/workspace/nightly/shenandoah-jdk11/src/hotspot/share/jvmci/jvmciJavaClasses.hpp:362:1:
note: in expansion of macro ‘COMPILER_CLASSES_DO’

I did similar fix on aarch64 when doing backports, and it also fixes to be in x86_64.

--- a/src/hotspot/cpu/x86/x86_64.ad     Sat Nov 10 14:01:20 2018 +0100
+++ b/src/hotspot/cpu/x86/x86_64.ad     Mon Nov 12 13:09:03 2018 +0100
@@ -543,7 +543,7 @@
 #include "gc/z/zBarrierSetAssembler.hpp"
 #endif
 #if INCLUDE_SHENANDOAHGC
-#include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
+#include "gc/shenandoah/shenandoahBrooksPointer.hpp"
 #endif
 %}

Testing: x86_64 PCH/no-PCH build

Thanks,
-Aleksey