Fix issue with storing 31-bit bitfield as Smi.

src/code-stubs.h

 // 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.
 
 #ifndef V8_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/codegen.h"
@@ skipping 1592 matching lines @@
   static const int kInput = 2;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(RegExpConstructResultStub);
 };
 
 
 class CallFunctionStub: public PlatformCodeStub {
  public:
   CallFunctionStub(Isolate* isolate, int argc, CallFunctionFlags flags)
-      : PlatformCodeStub(isolate), argc_(argc), flags_(flags) { }
+      : PlatformCodeStub(isolate), argc_(argc), flags_(flags) {
+    ASSERT(argc <= Code::kMaxArguments);
+  }
 
   void Generate(MacroAssembler* masm);
 
   static int ExtractArgcFromMinorKey(int minor_key) {
     return ArgcBits::decode(minor_key);
   }
 
  private:
   int argc_;
   CallFunctionFlags flags_;
 
   virtual void PrintName(OStream& os) const V8_OVERRIDE;  // NOLINT
 
   // Minor key encoding in 32 bits with Bitfield <Type, shift, size>.
   class FlagBits: public BitField<CallFunctionFlags, 0, 2> {};
-  class ArgcBits: public BitField<unsigned, 2, 32 - 2> {};
+  class ArgcBits : public BitField<unsigned, 2, Code::kArgumentsBits> {};
+
+  STATIC_ASSERT(Code::kArgumentsBits + 2 <= kStubMinorKeyBits);
 
   Major MajorKey() const { return CallFunction; }
   int MinorKey() const {
     // Encode the parameters in a unique 32 bit value.
     return FlagBits::encode(flags_) | ArgcBits::encode(argc_);
   }
 
   bool CallAsMethod() {
     return flags_ == CALL_AS_METHOD || flags_ == WRAP_AND_CALL;
   }
@@ skipping 883 matching lines @@
 
 
 class CallDescriptors {
  public:
   static void InitializeForIsolate(Isolate* isolate);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_