Add strong mode.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index 230a83da203ea18a61d2e3960a3c1ac1f921602f..7f74f4d294b14f269f7241030dded3f4693215f8 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -593,9 +593,9 @@ class FastNewClosureStub : public HydrogenCodeStub {
   bool is_default_constructor() const { return IsDefaultConstructor(kind()); }
 
  private:
-  STATIC_ASSERT(LANGUAGE_END == 2);
-  class LanguageModeBits : public BitField<LanguageMode, 0, 1> {};
-  class FunctionKindBits : public BitField<FunctionKind, 1, 4> {};
+  STATIC_ASSERT(LANGUAGE_END == 3);
+  class LanguageModeBits : public BitField<LanguageMode, 0, 2> {};
+  class FunctionKindBits : public BitField<FunctionKind, 2, 4> {};
 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(FastNewClosure);
   DEFINE_HYDROGEN_CODE_STUB(FastNewClosure, HydrogenCodeStub);