Fix crash in debug builds introduced with r21110.

src/compiler.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_COMPILER_H_
 #define V8_COMPILER_H_
 
 #include "allocation.h"
 #include "ast.h"
 #include "zone.h"
@@ skipping 520 matching lines @@
 
   MUST_USE_RESULT Status AbortOptimization(
       BailoutReason reason = kNoReason) {
     if (reason != kNoReason) info_->set_bailout_reason(reason);
     return SetLastStatus(BAILED_OUT);
   }
 
   MUST_USE_RESULT Status AbortAndDisableOptimization(
       BailoutReason reason = kNoReason) {
     if (reason != kNoReason) info_->set_bailout_reason(reason);
+    // Reference to shared function info does not change between phases.
+    AllowDeferredHandleDereference allow_handle_dereference;
     info_->shared_info()->DisableOptimization(info_->bailout_reason());
     return SetLastStatus(BAILED_OUT);
   }
 
   void WaitForInstall() {
     ASSERT(info_->is_osr());
     awaiting_install_ = true;
   }
 
   bool IsWaitingForInstall() { return awaiting_install_; }
@@ skipping 123 matching lines @@
   unsigned info_zone_start_allocation_size_;
   ElapsedTimer timer_;
 
   DISALLOW_COPY_AND_ASSIGN(CompilationPhase);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_COMPILER_H_