8296932: G1: Remove unused G1RootClosures::weak_oops

Reviewed-by: tschatzl

Author: albertnetymk

src/hotspot/share/gc/g1/g1RootClosures.cpp

@@ -37,7 +37,6 @@ class G1EvacuationClosures : public G1EvacuationRootClosures {
                        bool in_young_gc) :
       _closures(g1h, pss, in_young_gc) {}
 
-  OopClosure* weak_oops()   { return &_closures._oops; }
   OopClosure* strong_oops() { return &_closures._oops; }
 
   CLDClosure* weak_clds()             { return &_closures._clds; }
@@ -61,7 +60,6 @@ class G1ConcurrentStartMarkClosures : public G1EvacuationRootClosures {
       _strong(g1h, pss, /* process_only_dirty_klasses */ false),
       _weak(g1h, pss,   /* process_only_dirty_klasses */ false) {}
 
-  OopClosure* weak_oops()   { return &_weak._oops; }
   OopClosure* strong_oops() { return &_strong._oops; }
 
   CLDClosure* weak_clds()             { return &_weak._clds; }

src/hotspot/share/gc/g1/g1RootClosures.hpp

@@ -34,7 +34,6 @@ class G1ParScanThreadState;
 class G1RootClosures : public CHeapObj<mtGC> {
 public:
   // Closures to process raw oops in the root set.
-  virtual OopClosure* weak_oops() = 0;
   virtual OopClosure* strong_oops() = 0;
 
   // Closures to process CLDs in the root set.

src/hotspot/share/gc/g1/g1RootProcessor.cpp

@@ -85,7 +85,6 @@ class StrongRootsClosures : public G1RootClosures {
   StrongRootsClosures(OopClosure* roots, CLDClosure* clds, CodeBlobClosure* blobs) :
       _roots(roots), _clds(clds), _blobs(blobs) {}
 
-  OopClosure* weak_oops()   { return NULL; }
   OopClosure* strong_oops() { return _roots; }
 
   CLDClosure* weak_clds()        { return NULL; }
@@ -116,7 +115,6 @@ class AllRootsClosures : public G1RootClosures {
   AllRootsClosures(OopClosure* roots, CLDClosure* clds) :
       _roots(roots), _clds(clds) {}
 
-  OopClosure* weak_oops() { return _roots; }
   OopClosure* strong_oops() { return _roots; }
 
   // By returning the same CLDClosure for both weak and strong CLDs we ensure