RFR [8]: Fix build failure due to unknown INCLUDE_SHENANDOAHGC

[Aleksey Shipilev]

This changeset:

changeset:   11140:c2e689bdeaf8
user:        rkennke
date:        Thu Dec 06 13:27:58 2018 +0100
summary:     JDK8u-only: Use WB-based acmp barrier

...actually broke the sh/jdk8 build:

/home/buildbot/worker/shenandoah-jdk8-linux/build/hotspot/src/share/vm/opto/subnode.cpp:867:5:
error: "INCLUDE_SHENANDOAHGC" is not defined [-Werror=undef]
 #if INCLUDE_SHENANDOAHGC
     ^~~~~~~~~~~~~~~~~~~~

...and I haven't noticed it during backports, because I pulled that changeset only after backports
testing was done. Argh.

Fix:

diff -r bd0a98b181a1 src/share/vm/opto/subnode.cpp
--- a/src/share/vm/opto/subnode.cpp     Mon Dec 10 18:30:12 2018 +0100
+++ b/src/share/vm/opto/subnode.cpp     Tue Dec 11 12:26:36 2018 +0100
@@ -862,11 +862,11 @@
 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
   // Return the klass node for
   //   LoadP(AddP(foo:Klass, #java_mirror))
   //   or NULL if not matching.

-#if INCLUDE_SHENANDOAHGC
+#if INCLUDE_ALL_GCS
   n = ShenandoahBarrierNode::skip_through_barrier(n);
 #endif

   if (n->Opcode() != Op_LoadP) return NULL;
   const TypeInstPtr* tp = phase->type(n)->isa_instptr();

Testing: hotspot_gc_shenandoah

-Aleksey