Remove unused 'receiver' field from generators

src/objects-debug.cc

 // 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.
 
 #include "src/objects.h"
 
 #include "src/bootstrapper.h"
 #include "src/disasm.h"
 #include "src/disassembler.h"
 #include "src/field-type.h"
@@ skipping 405 matching lines @@
         next_link()->IsTransitionArray());
 }
 
 
 void JSGeneratorObject::JSGeneratorObjectVerify() {
   // In an expression like "new g()", there can be a point where a generator
   // object is allocated but its fields are all undefined, as it hasn't yet been
   // initialized by the generator.  Hence these weak checks.
   VerifyObjectField(kFunctionOffset);
   VerifyObjectField(kContextOffset);
-  VerifyObjectField(kReceiverOffset);
   VerifyObjectField(kOperandStackOffset);
   VerifyObjectField(kContinuationOffset);
 }
 
 
 void JSModule::JSModuleVerify() {
   VerifyObjectField(kContextOffset);
   VerifyObjectField(kScopeInfoOffset);
   CHECK(context()->IsUndefined() ||
         Context::cast(context())->IsModuleContext());
@@ skipping 879 matching lines @@
 
   // Both are done at the same time.
   CHECK_EQ(new_it.done(), old_it.done());
 }
 
 
 #endif  // DEBUG
 
 }  // namespace internal
 }  // namespace v8