[objects] Relax JSBoundFunction verification.

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/assembler-inl.h"
 #include "src/bootstrapper.h"
 #include "src/disasm.h"
 #include "src/disassembler.h"
@@ skipping 669 matching lines @@
   CHECK(this->length() >= SlicedString::kMinLength);
 }
 
 
 void JSBoundFunction::JSBoundFunctionVerify() {
   CHECK(IsJSBoundFunction());
   JSObjectVerify();
   VerifyObjectField(kBoundThisOffset);
   VerifyObjectField(kBoundTargetFunctionOffset);
   VerifyObjectField(kBoundArgumentsOffset);
-  CHECK(bound_target_function()->IsCallable());
   CHECK(IsCallable());
-  CHECK_EQ(IsConstructor(), bound_target_function()->IsConstructor());
+
+  Isolate* const isolate = GetIsolate();
+  if (!raw_bound_target_function()->IsUndefined(isolate)) {
+    CHECK(bound_target_function()->IsCallable());
+    CHECK_EQ(IsConstructor(), bound_target_function()->IsConstructor());
+  }
 }
 
-
 void JSFunction::JSFunctionVerify() {
   CHECK(IsJSFunction());
   VerifyObjectField(kPrototypeOrInitialMapOffset);
   VerifyObjectField(kNextFunctionLinkOffset);
   CHECK(code()->IsCode());
   CHECK(next_function_link() == NULL ||
         next_function_link()->IsUndefined(GetIsolate()) ||
         next_function_link()->IsJSFunction());
   CHECK(map()->is_callable());
 }
@@ skipping 986 matching lines @@
 
   // Both are done at the same time.
   CHECK_EQ(new_it.done(), old_it.done());
 }
 
 
 #endif  // DEBUG
 
 }  // namespace internal
 }  // namespace v8