This assert was obsolete after our type propagation rewrite, and it is now hit by some tests in hos…

sdk/lib/_internal/compiler/implementation/ssa/optimize.dart

 // 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.
 
 part of ssa;
 
 abstract class OptimizationPhase {
   String get name;
   void visitGraph(HGraph graph);
 }
@@ skipping 380 matching lines @@
     // Note that we still have to call [super] to make sure that we end up
     // in the remaining optimizations.
     return super.visitRelational(node);
   }
 
   HInstruction handleIdentityCheck(HInvokeBinary node) {
     HInstruction left = node.left;
     HInstruction right = node.right;
     HType leftType = types[left];
     HType rightType = types[right];
-    assert(!leftType.isConflicting() && !rightType.isConflicting());
 
     // We don't optimize on numbers to preserve the runtime semantics.
     if (!(left.isNumberOrNull(types) && right.isNumberOrNull(types)) &&
         leftType.intersection(rightType, compiler).isConflicting()) {
       return graph.addConstantBool(false, constantSystem);
     }
 
     if (left.isConstantBoolean() && right.isBoolean(types)) {
       HConstant constant = left;
       if (constant.constant.isTrue()) {
@@ skipping 938 matching lines @@
     }
 
     // For other fields having setters in the generative constructor body, set
     // the type to UNKNOWN to avoid relying on the type set in the initializer
     // list.
     allSetters.forEach((Element element) {
       backend.registerFieldConstructor(element, HType.UNKNOWN);
     });
   }
 }