[turbofan] Inline the allocation fast path.

test/unittests/compiler/change-lowering-unittest.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-stubs.h"
 #include "src/compiler/change-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/simplified-operator.h"
@@ skipping 20 matching lines @@
 
  protected:
   bool Is32() const {
     return WordRepresentation() == MachineRepresentation::kWord32;
   }
   bool Is64() const {
     return WordRepresentation() == MachineRepresentation::kWord64;
   }
 
   Reduction Reduce(Node* node) {
+    GraphReducer graph_reducer(zone(), graph());
     MachineOperatorBuilder machine(zone(), WordRepresentation());
     JSOperatorBuilder javascript(zone());
     JSGraph jsgraph(isolate(), graph(), common(), &javascript, nullptr,
                     &machine);
-    ChangeLowering reducer(&jsgraph);
+    ChangeLowering reducer(&graph_reducer, &jsgraph);
     return reducer.Reduce(node);
   }
 
   SimplifiedOperatorBuilder* simplified() { return &simplified_; }
 
   Matcher<Node*> IsAllocateHeapNumber(const Matcher<Node*>& effect_matcher,
                                       const Matcher<Node*>& control_matcher) {
     return IsCall(
         _, IsHeapConstant(AllocateHeapNumberStub(isolate()).GetCode()),
         IsNumberConstant(BitEq(0.0)), effect_matcher, control_matcher);
@@ skipping 208 matching lines @@
   Reduction r = Reduce(alloc);
 
   // Only check that we lowered, but do not specify the exact form since
   // this is subject to change.
   ASSERT_TRUE(r.Changed());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8