A64: Prevent repeated restoring of root in gap resolver

src/a64/lithium-gap-resolver-a64.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 63 matching lines @@
 
     if (!move.IsEliminated()) {
       ASSERT(move.source()->IsConstantOperand());
       EmitMove(i);
     }
   }
 
   if (need_to_restore_root_) {
     ASSERT(kSavedValue.Is(root));
     __ InitializeRootRegister();
+    need_to_restore_root_ = false;
   }
 
   moves_.Rewind(0);
 }
 
 
 void LGapResolver::BuildInitialMoveList(LParallelMove* parallel_move) {
   // Perform a linear sweep of the moves to add them to the initial list of
   // moves to perform, ignoring any move that is redundant (the source is
   // the same as the destination, the destination is ignored and
@@ skipping 222 matching lines @@
   LOperand* src = moves_[index].source();
   LOperand* dst = moves_[index].destination();
 
   ASSERT(src->IsStackSlot());
   ASSERT(dst->IsStackSlot());
   __ Ldr(temp, cgen_->ToMemOperand(src));
   __ Str(temp, cgen_->ToMemOperand(dst));
 }
 
 } }  // namespace v8::internal