Revert "Allow LetCont to bind multiple continuations."

pkg/compiler/lib/src/cps_ir/cps_ir_builder_visitor.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 dart2js.ir_builder;
 
 /**
  * This task iterates through all resolved elements and builds [ir.Node]s. The
  * nodes are stored in the [nodes] map and accessible through [hasIr] and
  * [getIr].
@@ skipping 450 matching lines @@
       // continuation's binding.  The continuation is bound just outside the
       // body to satisfy this property without extra analysis.
       // As a consequence, the break continuation needs parameters for all
       // local variables in scope at the exit from the body.
       List<ir.Parameter> parameters =
           new List<ir.Parameter>.generate(irBuilder.environment.length, (i) {
         return new ir.Parameter(irBuilder.environment.index2variable[i]);
       });
       joinContinuation = new ir.Continuation(parameters);
       irBuilder.invokeFullJoin(joinContinuation, jumps, recursive: false);
-      irBuilder.add(new ir.LetCont(<ir.Continuation>[joinContinuation],
-          innerBuilder._root));
+      irBuilder.add(new ir.LetCont(joinContinuation, innerBuilder._root));
       for (int i = 0; i < irBuilder.environment.length; ++i) {
         irBuilder.environment.index2value[i] = parameters[i];
       }
     } else {
       if (innerBuilder._root != null) {
         irBuilder.add(innerBuilder._root);
         irBuilder._current = innerBuilder._current;
         irBuilder.environment = innerBuilder.environment;
       }
     }
@@ skipping 450 matching lines @@
       ir.Primitive arg;
       if (ast.Operator.INCREMENT_OPERATORS.contains(op.source)) {
         arg = irBuilder.buildIntegerLiteral(1);
       } else {
         arg = visit(getAssignArgument());
       }
       valueToStore = new ir.Parameter(null);
       ir.Continuation k = new ir.Continuation([valueToStore]);
       ir.Expression invoke =
           new ir.InvokeMethod(originalValue, operatorSelector, k, [arg]);
-      irBuilder.add(new ir.LetCont(<ir.Continuation>[k], invoke));
+      irBuilder.add(new ir.LetCont(k, invoke));
     }
 
     if (Elements.isLocal(element)) {
       irBuilder.buildLocalSet(element, valueToStore);
     } else if ((!node.isSuperCall && Elements.isErroneous(element)) ||
                 Elements.isStaticOrTopLevel(element)) {
       irBuilder.buildStaticSet(
           element, elements.getSelector(node), valueToStore);
     } else {
       // Setter or index-setter invocation
@@ skipping 175 matching lines @@
     currentFunction = elements[node];
     if (node.initializers != null) {
       insideInitializer = true;
       visit(node.initializers);
       insideInitializer = false;
     }
     visit(node.body);
     currentFunction = oldFunction;
   }
 }