When compiling for-in pass correct context value to the increment instruction.

src/hydrogen.cc

 // Copyright 2012 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 3057 matching lines @@
 
   if (first_expression_index != length) {
     environment()->Drop(length - first_expression_index);
     for (int i = first_expression_index; i < length; ++i) {
       HUnknownOSRValue* osr_value = new(zone()) HUnknownOSRValue;
       AddInstruction(osr_value);
       environment()->Push(osr_value);
     }
   }
 
-
   AddSimulate(osr_entry_id);
   AddInstruction(new(zone()) HOsrEntry(osr_entry_id));
   HContext* context = new(zone()) HContext;
   AddInstruction(context);
   environment()->BindContext(context);
   current_block()->Goto(loop_predecessor);
   loop_predecessor->SetJoinId(statement->EntryId());
   set_current_block(loop_predecessor);
 }
 
@@ skipping 160 matching lines @@
   if (!stmt->each()->IsVariableProxy() ||
       !stmt->each()->AsVariableProxy()->var()->IsStackLocal()) {
     return Bailout("ForInStatement with non-local each variable");
   }
 
   Variable* each_var = stmt->each()->AsVariableProxy()->var();
 
   CHECK_ALIVE(VisitForValue(stmt->enumerable()));
   HValue* enumerable = Top();  // Leave enumerable at the top.
 
-  HValue* context = environment()->LookupContext();
-
   HInstruction* map = AddInstruction(new(zone()) HForInPrepareMap(
-      context, enumerable));
+      environment()->LookupContext(), enumerable));
   AddSimulate(stmt->PrepareId());
 
   HInstruction* array = AddInstruction(
       new(zone()) HForInCacheArray(
           enumerable,
           map,
           DescriptorArray::kEnumCacheBridgeCacheIndex));
 
   HInstruction* array_length = AddInstruction(
       new(zone()) HFixedArrayBaseLength(array));
@@ skipping 56 matching lines @@
   BreakAndContinueInfo break_info(stmt, 5);
   CHECK_BAILOUT(VisitLoopBody(stmt, loop_entry, &break_info));
 
   HBasicBlock* body_exit =
       JoinContinue(stmt, current_block(), break_info.continue_block());
 
   if (body_exit != NULL) {
     set_current_block(body_exit);
 
     HValue* current_index = Pop();
-    PushAndAdd(
-        new(zone()) HAdd(context, current_index, graph()->GetConstant1()));
-
+    HInstruction* new_index = new(zone()) HAdd(environment()->LookupContext(),
+                                               current_index,
+                                               graph()->GetConstant1());
+    new_index->AssumeRepresentation(Representation::Integer32());
+    PushAndAdd(new_index);
     body_exit = current_block();
   }
 
   HBasicBlock* loop_exit = CreateLoop(stmt,
                                       loop_entry,
                                       body_exit,
                                       loop_successor,
                                       break_info.break_block());
 
   set_current_block(loop_exit);
@@ skipping 4548 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal