Reenable polymorphic getter inlining.

src/hydrogen.cc

 // Copyright 2013 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 4693 matching lines @@
       ++count;
       HBasicBlock* if_true = graph()->CreateBasicBlock();
       HBasicBlock* if_false = graph()->CreateBasicBlock();
       HCompareMap* compare = New<HCompareMap>(
           object, info.map(),  if_true, if_false);
       current_block()->Finish(compare);
 
       set_current_block(if_true);
 
       HInstruction* load = BuildLoadMonomorphic(
-          &info, object, compare, ast_id, return_id, false);
+          &info, object, compare, ast_id, return_id, FLAG_polymorphic_inlining);
       if (load == NULL) {
         if (HasStackOverflow()) return;
       } else {
         if (!load->IsLinked()) {
           load->set_position(position);
           AddInstruction(load);
         }
         if (!ast_context()->IsEffect()) Push(load);
       }
 
       if (current_block() != NULL) current_block()->Goto(join);
       set_current_block(if_false);
     }
   }
 
   // Finish up.  Unconditionally deoptimize if we've handled all the maps we
   // know about and do not want to handle ones we've never seen.  Otherwise
   // use a generic IC.
   if (count == types->length() && FLAG_deoptimize_uncommon_cases) {
+    // Because the deopt may be the only path in the polymorphic load, make sure
+    // that the environment stack matches the depth on deopt that it otherwise
+    // would have had after a successful load.
+    if (!ast_context()->IsEffect()) Push(graph()->GetConstant0());
     FinishExitWithHardDeoptimization("Unknown map in polymorphic load", join);
   } else {
     HValue* context = environment()->context();
     HInstruction* load = new(zone()) HLoadNamedGeneric(context, object, name);
     load->set_position(position);
     AddInstruction(load);
     if (!ast_context()->IsEffect()) Push(load);
 
     if (join != NULL) {
       current_block()->Goto(join);
@@ skipping 4872 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal