Remove custom weak handling of monomorphic IC.

src/ic/ic.cc

Index: src/ic/ic.cc
diff --git a/src/ic/ic.cc b/src/ic/ic.cc
index cd8b0835b12762d72561e3e457266401260a9f78..48cef68f5ac652cdf4604bc7352d540ba01a72fb 100644
--- a/src/ic/ic.cc
+++ b/src/ic/ic.cc
@@ -474,42 +474,6 @@ void IC::PostPatching(Address address, Code* target, Code* old_target) {
 }
 
 
-void IC::RegisterWeakMapDependency(Handle<Code> stub) {
-  if (FLAG_collect_maps && FLAG_weak_embedded_maps_in_ic &&
-      stub->CanBeWeakStub()) {
-    DCHECK(!stub->is_weak_stub());
-    MapHandleList maps;
-    stub->FindAllMaps(&maps);
-    if (maps.length() == 1 && stub->IsWeakObjectInIC(*maps.at(0))) {
-      Map::AddDependentIC(maps.at(0), stub);
-      stub->mark_as_weak_stub();
-      if (FLAG_enable_ool_constant_pool) {
-        stub->constant_pool()->set_weak_object_state(
-            ConstantPoolArray::WEAK_OBJECTS_IN_IC);
-      }
-    }
-  }
-}
-
-
-void IC::InvalidateMaps(Code* stub) {
-  DCHECK(stub->is_weak_stub());
-  stub->mark_as_invalidated_weak_stub();
-  Isolate* isolate = stub->GetIsolate();
-  Heap* heap = isolate->heap();
-  Object* undefined = heap->undefined_value();
-  int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
-  for (RelocIterator it(stub, mode_mask); !it.done(); it.next()) {
-    RelocInfo::Mode mode = it.rinfo()->rmode();
-    if (mode == RelocInfo::EMBEDDED_OBJECT &&
-        it.rinfo()->target_object()->IsMap()) {
-      it.rinfo()->set_target_object(undefined, SKIP_WRITE_BARRIER);
-    }
-  }
-  CpuFeatures::FlushICache(stub->instruction_start(), stub->instruction_size());
-}
-
-
 void IC::Clear(Isolate* isolate, Address address,
                ConstantPoolArray* constant_pool) {
   Code* target = GetTargetAtAddress(address, constant_pool);