anchor.diff:    @override
     HInstruction visitOneShotInterceptor(HOneShotInterceptor node) {
       return handleInterceptedCall(node);
  -  }
  -
  -  bool needsSubstitutionForTypeVariableAccess(ClassEntity cls) {
  -    if (_closedWorld.isUsedAsMixin(cls)) return true;
  -
  -    return _closedWorld.classHierarchy.anyStrictSubclassOf(cls,
  -        (ClassEntity subclass) {
  -      return !_rtiSubstitutions.isTrivialSubstitution(subclass, cls);
  -    });
     }
   
     @override
  
positive.code:       List<OptimizationPhase> phases = <OptimizationPhase>[
          // Run trivial instruction simplification first to optimize
          // some patterns useful for type conversion.
          new SsaInstructionSimplifier(
              globalInferenceResults,
              _options,
              codegen.rtiSubstitutions,
              closedWorld,
              typeRecipeDomain,
              registry,
              log),
          new SsaTypeConversionInserter(closedWorld),
          new SsaRedundantPhiEliminator(),
          new SsaDeadPhiEliminator(),
  
negative.code:         new SsaValueRangeAnalyzer(closedWorld, this),
          // Previous optimizations may have generated new
          // opportunities for instruction simplification.
          new SsaInstructionSimplifier(globalInferenceResults, _options,
              closedWorld, typeRecipeDomain, registry, log),
        ];
        phases.forEach(runPhase);
  
  