[turbofan] Add AllocateHeapNumberStub to avoid runtime call.

src/code-stubs-hydrogen.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/bailout-reason.h"
 #include "src/code-stubs.h"
 #include "src/field-index.h"
 #include "src/hydrogen.h"
@@ skipping 865 matching lines @@
                               casted_stub()->is_js_array());
 
   return GetParameter(0);
 }
 
 
 Handle<Code> TransitionElementsKindStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
+
+template <>
+HValue* CodeStubGraphBuilder<AllocateHeapNumberStub>::BuildCodeStub() {
+  HValue* result =
+      Add<HAllocate>(Add<HConstant>(HeapNumber::kSize), HType::HeapNumber(),
+                     NOT_TENURED, HEAP_NUMBER_TYPE);
+  AddStoreMapConstant(result, isolate()->factory()->heap_number_map());
+  return result;
+}
+
+
+Handle<Code> AllocateHeapNumberStub::GenerateCode() {
+  return DoGenerateCode(this);
+}
+
+
 HValue* CodeStubGraphBuilderBase::BuildArrayConstructor(
     ElementsKind kind,
     AllocationSiteOverrideMode override_mode,
     ArgumentClass argument_class) {
   HValue* constructor = GetParameter(ArrayConstructorStubBase::kConstructor);
   HValue* alloc_site = GetParameter(ArrayConstructorStubBase::kAllocationSite);
   JSArrayBuilder array_builder(this, kind, alloc_site, constructor,
                                override_mode);
   HValue* result = NULL;
   switch (argument_class) {
@@ skipping 1123 matching lines @@
 
   // Probe the stub cache.
   Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
       Code::ComputeHandlerFlags(Code::LOAD_IC));
   Add<HTailCallThroughMegamorphicCache>(receiver, name, flags);
 
   // We never continue.
   return graph()->GetConstant0();
 }
 } }  // namespace v8::internal