Revert "Use an explicit 'this' parameter instead of 'This' nodes."

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart

 // Copyright (c) 2014, 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.
 
 library dart2js.ir_nodes_sexpr;
 
 import '../constants/values.dart';
 import '../util/util.dart';
 import 'cps_ir_nodes.dart';
 
@@ skipping 28 matching lines @@
     return namer.nameMutableVariable(node);
   }
 
   /// Main entry point for creating a [String] from a [Node].  All recursive
   /// calls must go through this method.
   String visit(Node node) {
     String s = node.accept(this);
     return decorator(node, s);
   }
 
-  String formatThisParameter(Parameter thisParameter) {
-    return thisParameter == null ? '()' : '(${visit(thisParameter)})';
-  }
-
   String visitFunctionDefinition(FunctionDefinition node) {
     String name = node.element.name;
-    String thisParameter = formatThisParameter(node.thisParameter);
     String parameters = node.parameters.map(visit).join(' ');
     String body = visit(node.body);
-    return '$indentation'
-        '(FunctionDefinition $name $thisParameter ($parameters) return\n'
+    return '$indentation(FunctionDefinition $name ($parameters) return\n'
         '$body)';
   }
 
   String visitFieldDefinition(FieldDefinition node) {
     String name = node.element.name;
     if (node.hasInitializer) {
       String body = visit(node.body);
       return '$indentation(FieldDefinition $name () return\n'
              '$body)';
     } else {
       return '$indentation(FieldDefinition $name)';
     }
   }
 
   String visitConstructorDefinition(ConstructorDefinition node) {
     String name = node.element.name;
     if (name != '') name = '$name ';
-    String thisParameter = formatThisParameter(node.thisParameter);
     String parameters = node.parameters.map(visit).join(' ');
     if (node.body != null) {
       String initializers = indentBlock(() {
         return indentBlock(() {
           if (node.initializers.isEmpty) {
             return '$indentation';
           } else {
             return node.initializers.map(visit).join('\n');
           }
         });
       });
       String body = visit(node.body);
-      return '$indentation'
-          '(ConstructorDefinition $name$thisParameter ($parameters) return'
+      return '$indentation(ConstructorDefinition $name($parameters) return'
           ' (\n$initializers)\n$body)';
     } else {
-      return '$indentation'
-          '(ConstructorDefinition $name$thisParameter ($parameters) return)';
+      return '$indentation(ConstructorDefinition $name($parameters) return)';
     }
   }
 
   String visitFieldInitializer(FieldInitializer node) {
     String name = node.element.name;
     String body = visit(node.body);
-    return '$indentation(FieldInitializer $name\n$body)';
+    return '$indentation(FieldInitializer $name\$body)';
   }
 
   String visitSuperInitializer(SuperInitializer node) {
     String target = node.target.name;
     String selector = node.selector.name;
     String arguments =
         indentBlock(() =>
           indentBlock(() => node.arguments.map(visit).join('\n')));
     return '$indentation(SuperInitializer $target $selector (\n$arguments)';
   }
@@ skipping 124 matching lines @@
     String falseCont = access(node.falseContinuation);
     return '$indentation(Branch $condition $trueCont $falseCont)';
   }
 
   String visitConstant(Constant node) {
     String value =
         node.expression.value.accept(new ConstantStringifier(), null);
     return '(Constant $value)';
   }
 
+  String visitThis(This node) {
+    return '(This)';
+  }
+
   String visitReifyTypeVar(ReifyTypeVar node) {
     return '$indentation(ReifyTypeVar ${node.typeVariable.name})';
   }
 
   String visitCreateFunction(CreateFunction node) {
     String function =
         indentBlock(() => indentBlock(() => visit(node.definition)));
     return '(CreateFunction\n$function)';
   }
 
@@ skipping 158 matching lines @@
   String visitDeferred(DeferredConstantValue constant, _) {
     return _failWith(constant);
   }
 }
 
 class _Namer {
   final Map<Node, String> _names = <Node, String>{};
   int _valueCounter = 0;
   int _continuationCounter = 0;
 
-  // TODO(sra): Make the methods not assert and print something indicating an
-  // error, so printer can be used to inspect broken terms.
-
   String nameParameter(Parameter parameter) {
     assert(!_names.containsKey(parameter));
     return _names[parameter] = parameter.hint.name;
   }
 
   String nameMutableVariable(MutableVariable variable) {
     assert(!_names.containsKey(variable));
     return _names[variable] = variable.hint.name;
   }
 
@@ skipping 10 matching lines @@
   void setReturnContinuation(Continuation node) {
     assert(!_names.containsKey(node) || _names[node] == 'return');
     _names[node] = 'return';
   }
 
   String getName(Node node) {
     assert(_names.containsKey(node));
     return _names[node];
   }
 }