6851742: (EA) allocation elimination doesn't work with UseG1GC

Fix eliminate_card_mark() to eliminate G1 pre/post barriers.

Reviewed-by: never

hotspot/src/share/vm/opto/phaseX.hpp

@@ -450,6 +450,8 @@ public:
     subsume_node(old, nn);
   }
 
+  bool delay_transform() const { return _delay_transform; }
+
   void set_delay_transform(bool delay) {
     _delay_transform = delay;
   }