Do not leak message object beyond try-catch.

src/ppc/full-codegen-ppc.cc

 // Copyright 2014 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_PPC
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 5344 matching lines @@
 
   // Store result register while executing finally block.
   __ push(r4);
 
   // Store pending message while executing finally block.
   ExternalReference pending_message_obj =
       ExternalReference::address_of_pending_message_obj(isolate());
   __ mov(ip, Operand(pending_message_obj));
   __ LoadP(r4, MemOperand(ip));
   __ push(r4);
+
+  ClearPendingMessage();
 }
 
 
 void FullCodeGenerator::ExitFinallyBlock() {
   DCHECK(!result_register().is(r4));
   // Restore pending message from stack.
   __ pop(r4);
   ExternalReference pending_message_obj =
       ExternalReference::address_of_pending_message_obj(isolate());
   __ mov(ip, Operand(pending_message_obj));
   __ StoreP(r4, MemOperand(ip));
 
   // Restore result register from stack.
   __ pop(r4);
 
   // Uncook return address and return.
   __ pop(result_register());
   __ SmiUntag(r4);
   __ mov(ip, Operand(masm_->CodeObject()));
   __ add(ip, ip, r4);
   __ mtctr(ip);
   __ bctr();
 }
 
 
+void FullCodeGenerator::ClearPendingMessage() {
+  DCHECK(!result_register().is(r4));
+  ExternalReference pending_message_obj =
+      ExternalReference::address_of_pending_message_obj(isolate());
+  __ LoadRoot(r4, Heap::kTheHoleValueRootIndex);
+  __ mov(ip, Operand(pending_message_obj));
+  __ StoreP(r4, MemOperand(ip));
+}
+
+
 #undef __
 
 
 void BackEdgeTable::PatchAt(Code* unoptimized_code, Address pc,
                             BackEdgeState target_state,
                             Code* replacement_code) {
   Address mov_address = Assembler::target_address_from_return_address(pc);
   Address cmp_address = mov_address - 2 * Assembler::kInstrSize;
   CodePatcher patcher(cmp_address, 1);
 
@@ skipping 54 matching lines @@
     return ON_STACK_REPLACEMENT;
   }
 
   DCHECK(interrupt_address ==
          isolate->builtins()->OsrAfterStackCheck()->entry());
   return OSR_AFTER_STACK_CHECK;
 }
 }
 }  // namespace v8::internal
 #endif  // V8_TARGET_ARCH_PPC