RFR: Include shenandoahSupport.hpp instead of shenandoahBarrierSetC2.hpp in C2's classes.cpp

[Roman Kennke]

Following up Vladimir's review, we can reduce include in classes.cpp to
just shenandoahSupport.hpp to get the various ShenandoahXYZNode's
declarations.

Testing: hotspot_gc_shenandoah

OK?


# HG changeset patch
# User rkennke
# Date 1543753972 -3600
#      Sun Dec 02 13:32:52 2018 +0100
# Node ID 27fe47697ab48d5aab33c2f13fb9faa8927e17ec
# Parent  02ceca8573e0d05e0d93ad56c6bd97821c4a29e9
Include shenandoahSupport.hpp instead of shenandoahBarrierSetC2.hpp in
C2's classes.cpp

diff --git a/src/hotspot/share/opto/classes.cpp
b/src/hotspot/share/opto/classes.cpp
--- a/src/hotspot/share/opto/classes.cpp
+++ b/src/hotspot/share/opto/classes.cpp
@@ -52,7 +52,7 @@
 #include "gc/z/c2/zBarrierSetC2.hpp"
 #endif
 #if INCLUDE_SHENANDOAHGC
-#include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
+#include "gc/shenandoah/c2/shenandoahSupport.hpp"
 #endif

 //
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