dart2js cleanup: remove unused imports and variables

pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.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.
 
 library dart2js.ir_builder_task;
 
+import 'package:js_runtime/shared/embedded_names.dart'
+    show JsBuiltin, JsGetName;
+
 import '../closure.dart' as closure;
 import '../common.dart';
 import '../common/names.dart' show Identifiers, Names, Selectors;
 import '../common/tasks.dart' show CompilerTask;
 import '../compiler.dart' show Compiler;
 import '../constants/expressions.dart';
+import '../constants/values.dart' show ConstantValue;
+import '../constants/values.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart';
-import '../elements/modelx.dart'
-    show
-        SynthesizedConstructorElementX,
-        ConstructorBodyElementX,
-        FunctionSignatureX;
+import '../elements/modelx.dart' show ConstructorBodyElementX;
 import '../io/source_information.dart';
+import '../js/js.dart' as js show js, Template, Expression, Name;
 import '../js_backend/backend_helpers.dart' show BackendHelpers;
 import '../js_backend/js_backend.dart'
     show JavaScriptBackend, SyntheticConstantKind;
+import '../native/native.dart' show NativeBehavior, HasCapturedPlaceholders;
+import '../resolution/operators.dart' as op;
+import '../resolution/semantic_visitor.dart';
 import '../resolution/tree_elements.dart' show TreeElements;
-import '../resolution/semantic_visitor.dart';
-import '../resolution/operators.dart' as op;
+import '../ssa/types.dart' show TypeMaskFactory;
 import '../tree/tree.dart' as ast;
 import '../types/types.dart' show TypeMask;
 import '../universe/call_structure.dart' show CallStructure;
 import '../universe/selector.dart' show Selector;
-import '../constants/values.dart' show ConstantValue;
+import '../util/util.dart';
+import 'cps_ir_builder.dart';
 import 'cps_ir_nodes.dart' as ir;
-import 'cps_ir_builder.dart';
-import '../native/native.dart' show NativeBehavior, HasCapturedPlaceholders;
-
+import 'type_mask_system.dart' show TypeMaskSystem;
 // TODO(karlklose): remove.
-import '../js/js.dart' as js show js, Template, Expression, Name;
-import '../ssa/types.dart' show TypeMaskFactory;
-import '../util/util.dart';
-
-import 'package:js_runtime/shared/embedded_names.dart'
-    show JsBuiltin, JsGetName;
-import '../constants/values.dart';
-import 'type_mask_system.dart' show TypeMaskSystem;
 
 typedef void IrBuilderCallback(Element element, ir.FunctionDefinition irNode);
 
 class ExplicitReceiverParameter implements Local {
   final ExecutableElement executableContext;
 
   ExplicitReceiverParameter(this.executableContext);
 
   String get name => 'receiver';
   String toString() => 'ExplicitReceiverParameter($executableContext)';
@@ skipping 848 matching lines @@
         env: getClosureEnvironment());
 
     if (element == helpers.jsArrayTypedConstructor) {
       // Generate a body for JSArray<E>.typed(allocation):
       //
       //    t1 = setRuntimeTypeInfo(allocation, TypeExpression($E));
       //    return Refinement(t1, <JSArray>);
       //
       assert(parameters.length == 1 || parameters.length == 2);
       ir.Primitive allocation = irBuilder.buildLocalGet(parameters[0]);
-      ClassElement classElement = element.enclosingElement;
 
       // Only call setRuntimeTypeInfo if JSArray requires the type parameter.
       if (requiresRuntimeTypes) {
         assert(parameters.length == 2);
         closure.TypeVariableLocal typeParameter = parameters[1];
         ir.Primitive typeArgument =
             irBuilder.buildTypeVariableAccess(typeParameter.typeVariable);
 
         ir.Primitive typeInformation = irBuilder.addPrimitive(
             new ir.TypeExpression(ir.TypeExpressionKind.INSTANCE,
@@ skipping 201 matching lines @@
     ir.Primitive stream = visit(node.expression);
     ir.Primitive dummyTypeArgument = irBuilder.buildNullConstant();
     ConstructorElement constructor = helpers.streamIteratorConstructor;
     ir.Primitive iterator = irBuilder.addPrimitive(new ir.InvokeConstructor(
         constructor.enclosingClass.thisType,
         constructor,
         new Selector.callConstructor(constructor.memberName, 1),
         <ir.Primitive>[stream, dummyTypeArgument],
         sourceInformationBuilder.buildGeneric(node)));
 
-    ir.Node buildTryBody(IrBuilder builder) {
+    buildTryBody(IrBuilder builder) {
       ir.Node buildLoopCondition(IrBuilder builder) {
         ir.Primitive moveNext = builder.buildDynamicInvocation(
             iterator,
             Selectors.moveNext,
             elements.getMoveNextTypeMask(node),
             <ir.Primitive>[],
             sourceInformationBuilder.buildForInMoveNext(node));
         return builder.addPrimitive(new ir.Await(moveNext));
       }
 
@@ skipping 2875 matching lines @@
       _backend.jsInteropAnalysis.hasAnonymousAnnotation(element.contextClass);
 
   String getJsInteropTargetPath(FunctionElement element) {
     return '${_backend.namer.fixedBackendPath(element)}.'
         '${_backend.nativeData.getFixedBackendName(element)}';
   }
 
   DartType get jsJavascriptObjectType =>
       _backend.helpers.jsJavaScriptObjectClass.thisType;
 }