RFR: Prune undefined and unused methods

[Aleksey Shipilev]

Static analysis detected these methods are not defined (and not used). Let's remove them:

diff -r 8cdd146bc484 src/hotspot/share/gc/shenandoah/c1/shenandoahBarrierSetC1.hpp
--- a/src/hotspot/share/gc/shenandoah/c1/shenandoahBarrierSetC1.hpp     Wed Sep 05 10:11:17 2018 +0200
+++ b/src/hotspot/share/gc/shenandoah/c1/shenandoahBarrierSetC1.hpp     Wed Sep 05 10:16:16 2018 +0200
@@ -119,12 +119,10 @@

 class ShenandoahBarrierSetC1 : public BarrierSetC1 {
 private:
   CodeBlob* _pre_barrier_c1_runtime_code_blob;

-  void keep_alive_barrier(LIR_Opr val);
-
   void pre_barrier(LIRGenerator* gen, CodeEmitInfo* info, DecoratorSet decorators, LIR_Opr
addr_opr, LIR_Opr pre_val);
   void post_barrier(LIRGenerator* gen, LIR_OprDesc* addr, LIR_OprDesc* new_val);

   LIR_Opr read_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, bool need_null_check);
   LIR_Opr write_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, bool need_null_check);
diff -r 8cdd146bc484 src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.hpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.hpp  Wed Sep 05 10:11:17 2018 +0200
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.hpp  Wed Sep 05 10:16:16 2018 +0200
@@ -153,13 +153,10 @@
     }
   }

   void report_illegal_transition(const char* method);

-  void make_idle();
-  void activate_region();
-
   bool can_idle_region() const;
 public:
   // Allowed transitions from the outside code:
   void make_regular_allocation();
   void make_regular_bypass();

Testing: tier3_gc_shenandoah

Thanks,
-Aleksey