Revert "Protect types_propagation receiver type strengthening against many users."

pkg/compiler/lib/src/ssa/nodes.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.
 
 import '../closure.dart';
 import '../common.dart';
 import '../compiler.dart' show Compiler;
 import '../constants/constant_system.dart';
 import '../constants/values.dart';
 import '../dart_types.dart';
@@ skipping 1244 matching lines @@
     // Keep track of all instructions that we have to deal with later
     // and count the number of them that are in the current block.
     Setlet<HInstruction> users = new Setlet<HInstruction>();
     int usersInCurrentBlock = 0;
 
     // Run through all the users and see if they are dominated or
     // potentially dominated by [other].
     HBasicBlock otherBlock = other.block;
     for (int i = 0, length = usedBy.length; i < length; i++) {
       HInstruction current = usedBy[i];
-      HBasicBlock currentBlock = current.block;
-      if (otherBlock.dominates(currentBlock)) {
-        if (identical(currentBlock, otherBlock)) usersInCurrentBlock++;
+      if (otherBlock.dominates(current.block)) {
+        if (identical(current.block, otherBlock)) usersInCurrentBlock++;
         users.add(current);
       }
     }
 
     // Run through all the phis in the same block as [other] and remove them
     // from the users set.
     if (usersInCurrentBlock > 0) {
       for (HPhi phi = otherBlock.phis.first; phi != null; phi = phi.next) {
         if (users.contains(phi)) {
           users.remove(phi);
@@ skipping 2143 matching lines @@
 class HDynamicType extends HRuntimeType {
   HDynamicType(DynamicType dartType, TypeMask instructionType)
       : super(const <HInstruction>[], dartType, instructionType);
 
   accept(HVisitor visitor) => visitor.visitDynamicType(this);
 
   int typeCode() => HInstruction.DYNAMIC_TYPE_TYPECODE;
 
   bool typeEquals(HInstruction other) => other is HDynamicType;
 }