RemoveFromGraph on definitions asserts empty use lists.

runtime/vm/intermediate_language.cc

 // Copyright (c) 2012, 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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 120 matching lines @@
   Instruction* prev_instr = previous();
   Instruction* next_instr = next();
   ASSERT(next_instr != NULL);
   ASSERT(!next_instr->IsBlockEntry());
   prev_instr->set_next(next_instr);
   next_instr->set_previous(prev_instr);
   // Reset successor and previous instruction to indicate
   // that the instruction is removed from the graph.
   set_previous(NULL);
   set_next(NULL);
+  ASSERT(!IsDefinition() || AsDefinition()->use_list() == NULL);
   return return_previous ? prev_instr : next_instr;
 }
 
 
 void ForwardInstructionIterator::RemoveCurrentFromGraph() {
   current_ = current_->RemoveFromGraph(true);  // Set current_ to previous.
 }
 
 
 // Default implementation of visiting basic blocks.  Can be overridden.
@@ skipping 1158 matching lines @@
   if (compiler->is_ssa()) {
     ASSERT(locs()->in(0).IsRegister());
     __ PushRegister(locs()->in(0).reg());
   }
 }
 
 
 #undef __
 
 }  // namespace dart