[turbofan] Add AllocateHeapNumberStub to avoid runtime call.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index e8b7c8335c2282df3ffff6ff405fa31027987231..6921883e0257a45c2a13e1564f66c4da90a0858e 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -51,6 +51,7 @@ namespace internal {
   V(StubFailureTrampoline)                  \
   V(SubString)                              \
   /* HydrogenCodeStubs */                   \
+  V(AllocateHeapNumber)                     \
   V(ArrayNArgumentsConstructor)             \
   V(ArrayNoArgumentConstructor)             \
   V(ArraySingleArgumentConstructor)         \
@@ -2113,6 +2114,17 @@ class TransitionElementsKindStub : public HydrogenCodeStub {
 };
 
 
+class AllocateHeapNumberStub FINAL : public HydrogenCodeStub {
+ public:
+  explicit AllocateHeapNumberStub(Isolate* isolate)
+      : HydrogenCodeStub(isolate) {}
+
+ private:
+  DEFINE_CALL_INTERFACE_DESCRIPTOR(AllocateHeapNumber);
+  DEFINE_HYDROGEN_CODE_STUB(AllocateHeapNumber, HydrogenCodeStub);
+};
+
+
 class ArrayConstructorStubBase : public HydrogenCodeStub {
  public:
   ArrayConstructorStubBase(Isolate* isolate,