Use the constant pool for all constants, not just null.

runtime/vm/flow_graph_inliner.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_inliner.h"
 
 #include "vm/compiler.h"
 #include "vm/flags.h"
 #include "vm/flow_graph.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 652 matching lines @@
     }
 
     // Replace remaining constants with uses by constants in the caller's
     // initial definitions.
     GrowableArray<Definition*>* defns =
         callee_graph->graph_entry()->initial_definitions();
     for (intptr_t i = 0; i < defns->length(); ++i) {
       ConstantInstr* constant = (*defns)[i]->AsConstant();
       if ((constant != NULL) && constant->HasUses()) {
         constant->ReplaceUsesWith(
-            caller_graph_->AddConstantToInitialDefinitions(
-                constant->value()));
+            caller_graph_->GetConstant(constant->value()));
       }
     }
 
     // Check that inlining maintains use lists.
     DEBUG_ASSERT(!FLAG_verify_compiler || caller_graph_->VerifyUseLists());
   }
 
   static intptr_t CountConstants(const GrowableArray<Value*>& arguments) {
     intptr_t count = 0;
     for (intptr_t i = 0; i < arguments.length(); i++) {
@@ skipping 335 matching lines @@
       stub = (*call_data.parameter_stubs)[i];
       stub->ReplaceUsesWith(actual->definition());
     }
   }
   GrowableArray<Definition*>* defns =
       callee_graph->graph_entry()->initial_definitions();
   for (intptr_t i = 0; i < defns->length(); ++i) {
     ConstantInstr* constant = (*defns)[i]->AsConstant();
     if ((constant != NULL) && constant->HasUses()) {
       constant->ReplaceUsesWith(
-          owner_->caller_graph()->AddConstantToInitialDefinitions(
-              constant->value()));
+          owner_->caller_graph()->GetConstant(constant->value()));
     }
   }
   return true;
 }
 
 
 static Instruction* AppendInstruction(Instruction* first,
                                       Instruction* second) {
   for (intptr_t i = second->InputCount() - 1; i >= 0; --i) {
     Value* input = second->InputAt(i);
@@ skipping 287 matching lines @@
         OS::Print("After Inlining of %s\n", flow_graph_->
                   parsed_function().function().ToFullyQualifiedCString());
         FlowGraphPrinter printer(*flow_graph_);
         printer.PrintBlocks();
       }
     }
   }
 }
 
 }  // namespace dart