Turn the NumberToStringStub into a hydrogen stub.

src/ia32/code-stubs-ia32.h

Index: src/ia32/code-stubs-ia32.h
diff --git a/src/ia32/code-stubs-ia32.h b/src/ia32/code-stubs-ia32.h
index f36cd610cac10d06b4d4553a353d0f9ecdaad1cb..dc536e7eaee29a40a0fe0e11cebe3eaf0538e89f 100644
--- a/src/ia32/code-stubs-ia32.h
+++ b/src/ia32/code-stubs-ia32.h
@@ -217,18 +217,6 @@ class StringCompareStub: public PlatformCodeStub {
 };
 
 
-class NumberToStringStub: public PlatformCodeStub {
- public:
-  NumberToStringStub() { }
-
- private:
-  Major MajorKey() { return NumberToString; }
-  int MinorKey() { return 0; }
-
-  void Generate(MacroAssembler* masm);
-};
-
-
 class NameDictionaryLookupStub: public PlatformCodeStub {
  public:
   enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };