[turbofan] Initial version of allocation folding and write barrier elimination.

src/compiler/js-create-lowering.h

Index: src/compiler/js-create-lowering.h
diff --git a/src/compiler/js-create-lowering.h b/src/compiler/js-create-lowering.h
index 99eb461148b56fdad9d46eea555ad1746756293e..57b28af603f30f6cab920cd2fc24ed488bec15ee 100644
--- a/src/compiler/js-create-lowering.h
+++ b/src/compiler/js-create-lowering.h
@@ -71,7 +71,6 @@ class JSCreateLowering final : public AdvancedReducer {
                                     Handle<JSObject> boilerplate,
                                     PretenureFlag pretenure,
                                     AllocationSiteUsageContext* site_context);
-  Node* AllocateMutableHeapNumber(double value, Node* effect, Node* control);
 
   // Infers the LiteralsArray to use for a given {node}.
   MaybeHandle<LiteralsArray> GetSpecializationLiterals(Node* node);