Extract interceptor calls from raw is-checks.

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

 // Copyright (c) 2013, 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;
 
 /**
  * This phase simplifies interceptors in multiple ways:
  *
  * 1) If the interceptor is for an object whose type is known, it
@@ skipping 173 matching lines @@
             interceptedClasses.add(backend.jsIntClass);
           }
           if (intercepted.contains(backend.jsDoubleClass)) {
             interceptedClasses.add(backend.jsDoubleClass);
           }
         }
       }
     } else {
       interceptedClasses = new Set<ClassElement>();
       for (var user in node.usedBy) {
+        if (user is HIs) {
+          // Is-checks can be performed on any intercepted class.
+          interceptedClasses.addAll(backend.interceptedClasses);
+          break;
+        }
         if (user is! HInvoke) continue;
         // We don't handle escaping interceptors yet.
         interceptedClasses.addAll(
             backend.getInterceptedClassesOn(user.selector.name));
       }
     }
 
     HInstruction receiver = node.receiver;
     HType instructionType = receiver.instructionType;
     if (canUseSelfForInterceptor(instructionType, interceptedClasses)) {
@@ skipping 37 matching lines @@
     interceptor.sourceElement = user.sourceElement;
     interceptor.instructionType = user.instructionType;
 
     HBasicBlock block = user.block;
     block.addAfter(user, interceptor);
     block.rewrite(user, interceptor);
     block.remove(user);
     return true;
   }
 
-  
   bool visitOneShotInterceptor(HOneShotInterceptor node) {
     HInstruction constant = tryComputeConstantInterceptor(
         node.inputs[1], node.interceptedClasses);
 
     if (constant == null) return false;
 
     Selector selector = node.selector;
     // TODO(ngeoffray): make one shot interceptors know whether
     // they have side effects.
     HInstruction instruction;
@@ skipping 14 matching lines @@
       inputs[0] = constant;
       instruction = new HInvokeDynamicMethod(selector, inputs, true);
     }
 
     HBasicBlock block = node.block;
     block.addAfter(node, instruction);
     block.rewrite(node, instruction);
     return true;
   }
 }