Remove custom weak handling of monomorphic IC.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 2fde78b8b29f62277f7e1518171e47410e70682a..485560f2933ebe6762b741138ebf7c4099070eb8 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -5068,34 +5068,6 @@ void Code::set_marked_for_deoptimization(bool flag) {
 }
 
 
-bool Code::is_weak_stub() {
-  return CanBeWeakStub() && WeakStubField::decode(
-      READ_UINT32_FIELD(this, kKindSpecificFlags1Offset));
-}
-
-
-void Code::mark_as_weak_stub() {
-  DCHECK(CanBeWeakStub());
-  int previous = READ_UINT32_FIELD(this, kKindSpecificFlags1Offset);
-  int updated = WeakStubField::update(previous, true);
-  WRITE_UINT32_FIELD(this, kKindSpecificFlags1Offset, updated);
-}
-
-
-bool Code::is_invalidated_weak_stub() {
-  return is_weak_stub() && InvalidatedWeakStubField::decode(
-      READ_UINT32_FIELD(this, kKindSpecificFlags1Offset));
-}
-
-
-void Code::mark_as_invalidated_weak_stub() {
-  DCHECK(is_inline_cache_stub());
-  int previous = READ_UINT32_FIELD(this, kKindSpecificFlags1Offset);
-  int updated = InvalidatedWeakStubField::update(previous, true);
-  WRITE_UINT32_FIELD(this, kKindSpecificFlags1Offset, updated);
-}
-
-
 bool Code::is_inline_cache_stub() {
   Kind kind = this->kind();
   switch (kind) {
@@ -5242,13 +5214,6 @@ class Code::FindAndReplacePattern {
 };
 
 
-bool Code::IsWeakObjectInIC(Object* object) {
-  return object->IsMap() && Map::cast(object)->CanTransition() &&
-         FLAG_collect_maps &&
-         FLAG_weak_embedded_maps_in_ic;
-}
-
-
 Object* Map::prototype() const {
   return READ_FIELD(this, kPrototypeOffset);
 }