Do not leak message object beyond try-catch.

src/x64/full-codegen-x64.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/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 5277 matching lines @@
   __ Push(rdx);
 
   // Store result register while executing finally block.
   __ Push(result_register());
 
   // Store pending message while executing finally block.
   ExternalReference pending_message_obj =
       ExternalReference::address_of_pending_message_obj(isolate());
   __ Load(rdx, pending_message_obj);
   __ Push(rdx);
+
+  ClearPendingMessage();
 }
 
 
 void FullCodeGenerator::ExitFinallyBlock() {
   DCHECK(!result_register().is(rdx));
   DCHECK(!result_register().is(rcx));
   // Restore pending message from stack.
   __ Pop(rdx);
   ExternalReference pending_message_obj =
       ExternalReference::address_of_pending_message_obj(isolate());
   __ Store(pending_message_obj, rdx);
 
   // Restore result register from stack.
   __ Pop(result_register());
 
   // Uncook return address.
   __ Pop(rdx);
   __ SmiToInteger32(rdx, rdx);
   __ Move(rcx, masm_->CodeObject());
   __ addp(rdx, rcx);
   __ jmp(rdx);
 }
 
 
+void FullCodeGenerator::ClearPendingMessage() {
+  DCHECK(!result_register().is(rdx));
+  ExternalReference pending_message_obj =
+      ExternalReference::address_of_pending_message_obj(isolate());
+  __ LoadRoot(rdx, Heap::kTheHoleValueRootIndex);
+  __ Store(pending_message_obj, rdx);
+}
+
+
 #undef __
 
 
 static const byte kJnsInstruction = 0x79;
 static const byte kNopByteOne = 0x66;
 static const byte kNopByteTwo = 0x90;
 #ifdef DEBUG
 static const byte kCallInstruction = 0xe8;
 #endif
 
@@ skipping 63 matching lines @@
   DCHECK_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64