Fix reintroduction of global variables that have been deleted.

src/arm/lithium-codegen-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2177 matching lines @@
   if (instr->hydrogen()->check_hole_value()) {
     __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
     __ cmp(result, ip);
     DeoptimizeIf(eq, instr->environment());
   }
 }
 
 
 void LCodeGen::DoStoreGlobal(LStoreGlobal* instr) {
   Register value = ToRegister(instr->InputAt(0));
-  __ mov(ip, Operand(Handle<Object>(instr->hydrogen()->cell())));
-  __ str(value, FieldMemOperand(ip, JSGlobalPropertyCell::kValueOffset));
+  Register scratch = ToRegister(instr->TempAt(0));
+  Register scratch2 = scratch0();
+
+  // If the cell we are storing to contains the hole it could have
+  // been deleted from the property dictionary. In that case, we need
+  // to update the property details in the property dictionary to mark
+  // it as no longer deleted. We deoptimize in that case.
+  __ mov(scratch, Operand(Handle<Object>(instr->hydrogen()->cell())));
+  __ ldr(scratch2,
+         FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
+  __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
+  __ cmp(scratch2, ip);
+  DeoptimizeIf(eq, instr->environment());
+
+  // Store the value.
+  __ str(value, FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
 }
 
 
 void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
   // TODO(antonm): load a context with a separate instruction.
   Register result = ToRegister(instr->result());
   __ LoadContext(result, instr->context_chain_length());
   __ ldr(result, ContextOperand(result, instr->slot_index()));
 }
 
@@ skipping 1460 matching lines @@
 
 
 void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
   Abort("DoOsrEntry unimplemented.");
 }
 
 
 #undef __
 
 } }  // namespace v8::internal