Fix use-of-uninitialized-value introduced in r24700

src/isolate.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 <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 
 #include "src/v8.h"
 
@@ skipping 48 matching lines @@
 }
 
 
 ThreadLocalTop::ThreadLocalTop() {
   InitializeInternal();
 }
 
 
 void ThreadLocalTop::InitializeInternal() {
   c_entry_fp_ = 0;
+  c_function_ = 0;
   handler_ = 0;
 #ifdef USE_SIMULATOR
   simulator_ = NULL;
 #endif
   js_entry_sp_ = NULL;
   external_callback_scope_ = NULL;
   current_vm_state_ = EXTERNAL;
   try_catch_handler_ = NULL;
   context_ = NULL;
   thread_id_ = ThreadId::Invalid();
@@ skipping 2323 matching lines @@
   if (prev_ && prev_->Intercept(flag)) return true;
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 } }  // namespace v8::internal