[turbofan] Remove dead ChangeToUndefined in intrinsic lowering.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1878563002

Cr-Commit-Position: refs/heads/master@{#35381}

src/compiler/js-intrinsic-lowering.cc

@@ -466,12 +466,6 @@ Reduction JSIntrinsicLowering::Change(Node* node, const Operator* op, Node* a,
 }
 
 
-Reduction JSIntrinsicLowering::ChangeToUndefined(Node* node, Node* effect) {
-  ReplaceWithValue(node, jsgraph()->UndefinedConstant(), effect);
-  return Changed(node);
-}
-
-
 Reduction JSIntrinsicLowering::Change(Node* node, Callable const& callable,
                                       int stack_parameter_count) {
   CallDescriptor const* const desc = Linkage::GetStubCallDescriptor(

src/compiler/js-intrinsic-lowering.h

@@ -70,7 +70,6 @@ class JSIntrinsicLowering final : public AdvancedReducer {
   Reduction Change(Node* node, const Operator* op, Node* a, Node* b, Node* c);
   Reduction Change(Node* node, const Operator* op, Node* a, Node* b, Node* c,
                    Node* d);
-  Reduction ChangeToUndefined(Node* node, Node* effect = nullptr);
   Reduction Change(Node* node, Callable const& callable,
                    int stack_parameter_count);