Disable hoisting of checked-mode assertions out of loops.

runtime/vm/flow_graph_optimizer.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_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 2317 matching lines @@
         Instruction* current = it.Current();
         if (!current->IsPushArgument() && !current->AffectedBySideEffect()) {
           bool inputs_loop_invariant = true;
           for (int i = 0; i < current->InputCount(); ++i) {
             Definition* input_def = current->InputAt(i)->definition();
             if (!input_def->GetBlock()->Dominates(pre_header)) {
               inputs_loop_invariant = false;
               break;
             }
           }
-          if (inputs_loop_invariant) {
+          if (inputs_loop_invariant &&
+              !current->IsAssertAssignable() &&
+              !current->IsAssertBoolean()) {
+            // TODO(fschneider): Enable hoisting of Assert-instructions
+            // if it safe to do.
             Hoist(&it, pre_header, current);
           } else if (current->IsCheckSmi() &&
                      current->InputAt(0)->definition()->IsPhi()) {
             TryHoistCheckSmiThroughPhi(
                 &it, header, pre_header, current->AsCheckSmi());
           }
         }
       }
     }
   }
@@ skipping 989 matching lines @@
 
   if (FLAG_trace_constant_propagation) {
     OS::Print("\n==== After constant propagation ====\n");
     FlowGraphPrinter printer(*graph_);
     printer.PrintBlocks();
   }
 }
 
 
 }  // namespace dart