Refactor to support multiple outputs in location summary

runtime/vm/flow_graph_compiler_arm.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/globals.h"  // Needed here to get TARGET_ARCH_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 692 matching lines @@
   __ PopList((1 << R1) | (1 << R2));
 }
 
 
 void FlowGraphCompiler::EmitInstructionEpilogue(Instruction* instr) {
   if (is_optimizing()) {
     return;
   }
   Definition* defn = instr->AsDefinition();
   if ((defn != NULL) && defn->is_used()) {
-    __ Push(defn->locs()->out().reg());
+    __ Push(defn->locs()->out(0).reg());
   }
 }
 
 
 // Input parameters:
 //   R4: arguments descriptor array.
 void FlowGraphCompiler::CopyParameters() {
   __ Comment("Copy parameters");
   const Function& function = parsed_function().function();
   LocalScope* scope = parsed_function().node_sequence()->scope();
@@ skipping 1085 matching lines @@
   DRegister dreg = EvenDRegisterOf(reg);
   __ vldrd(dreg, Address(SP, kDoubleSize, Address::PostIndex));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM