Add more safe points in compiler

runtime/vm/flow_graph.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/flow_graph.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 1298 matching lines @@
   InsertAfter(prev, redef, NULL, FlowGraph::kValue);
   RenameDominatedUses(original, redef, redef);
   return redef;
 }
 
 
 void FlowGraph::RemoveRedefinitions() {
   // Remove redefinition instructions inserted to inhibit hoisting.
   for (BlockIterator block_it = reverse_postorder_iterator(); !block_it.Done();
        block_it.Advance()) {
+    thread()->CheckForSafepoint();
     for (ForwardInstructionIterator instr_it(block_it.Current());
          !instr_it.Done(); instr_it.Advance()) {
       RedefinitionInstr* redefinition = instr_it.Current()->AsRedefinition();
       if (redefinition != NULL) {
         Definition* original;
         do {
           original = redefinition->value()->definition();
         } while (original->IsRedefinition());
         redefinition->ReplaceUsesWith(original);
         instr_it.RemoveCurrentFromGraph();
@@ skipping 970 matching lines @@
                                                 Representation rep,
                                                 intptr_t cid) {
   ExtractNthOutputInstr* extract =
       new (Z) ExtractNthOutputInstr(new (Z) Value(instr), index, rep, cid);
   instr->ReplaceUsesWith(extract);
   InsertAfter(instr, extract, NULL, FlowGraph::kValue);
 }
 
 
 }  // namespace dart