Make the strict-mode calling convention for contextual calls the default one.

src/code-stubs.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1535 matching lines @@
     return ArgcBits::decode(minor_key);
   }
 
  private:
   int argc_;
   CallFunctionFlags flags_;
 
   virtual void PrintName(StringStream* stream);
 
   // Minor key encoding in 32 bits with Bitfield <Type, shift, size>.
-  class FlagBits: public BitField<CallFunctionFlags, 0, 3> {};
-  class ArgcBits: public BitField<unsigned, 3, 32 - 3> {};
+  class FlagBits: public BitField<CallFunctionFlags, 0, 2> {};
+  class ArgcBits: public BitField<unsigned, 2, 32 - 2> {};
 
   Major MajorKey() { return CallFunction; }
   int MinorKey() {
     // Encode the parameters in a unique 32 bit value.
     return FlagBits::encode(flags_) | ArgcBits::encode(argc_);
   }
 
   bool ReceiverMightBeImplicit() {
     return (flags_ & RECEIVER_MIGHT_BE_IMPLICIT) != 0;
   }
 
-  bool ReceiverIsImplicit() {
-    return (flags_ & RECEIVER_IS_IMPLICIT) != 0;
-  }
-
   bool RecordCallTarget() {
     return (flags_ & RECORD_CALL_TARGET) != 0;
   }
 };
 
 
 class CallConstructStub: public PlatformCodeStub {
  public:
   explicit CallConstructStub(CallFunctionFlags flags) : flags_(flags) {}
 
@@ skipping 853 matching lines @@
   int MinorKey() { return 0; }
 
   void Generate(MacroAssembler* masm);
 
   DISALLOW_COPY_AND_ASSIGN(ProfileEntryHookStub);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_