Revert "Towards compiling Hello World!" and "Compile and run Hello World!"

pkg/compiler/lib/src/ssa/ssa.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.
 
 library ssa;
 
-import '../common/codegen.dart' show CodegenWorkItem, CodegenRegistry;
+import '../common/codegen.dart' show CodegenWorkItem;
 import '../common/tasks.dart' show CompilerTask, Measurer;
-import '../constants/values.dart';
 import '../elements/elements.dart' show MethodElement;
-import '../elements/entities.dart' show FieldEntity, MemberEntity;
+import '../elements/entities.dart' show MemberEntity;
 import '../io/source_information.dart';
 import '../js/js.dart' as js;
 import '../js_backend/backend.dart' show JavaScriptBackend, FunctionCompiler;
-import '../universe/call_structure.dart';
-import '../universe/use.dart';
 import '../world.dart' show ClosedWorld;
 
 import 'codegen.dart';
 import 'nodes.dart';
 import 'optimize.dart';
 
 class SsaFunctionCompiler implements FunctionCompiler {
   final SsaCodeGeneratorTask generator;
   final SsaBuilderTask _builder;
   final SsaOptimizerTask optimizer;
@@ skipping 26 matching lines @@
   Iterable<CompilerTask> get tasks {
     return <CompilerTask>[_builder, optimizer, generator];
   }
 }
 
 abstract class SsaBuilderTask implements CompilerTask {
   /// Creates the [HGraph] for [work] or returns `null` if no code is needed
   /// for [work].
   HGraph build(CodegenWorkItem work, ClosedWorld closedWorld);
 }
-
-abstract class SsaBuilderFieldMixin {
-  ConstantValue getFieldInitialConstantValue(FieldEntity field);
-
-  /// Handle field initializer of [element]. Returns `true` if no code
-  /// is needed for the field.
-  ///
-  /// If [element] is a field with a constant initializer, the value is
-  /// registered with the world impact. Otherwise the cyclic-throw helper is
-  /// registered for the lazy value computation.
-  ///
-  /// If the field is constant, no code is needed for the field and the method
-  /// returns `true`.
-  bool handleConstantField(
-      MemberEntity element, CodegenRegistry registry, ClosedWorld closedWorld) {
-    if (element.isField) {
-      ConstantValue initialValue = getFieldInitialConstantValue(element);
-      if (initialValue != null) {
-        registry.worldImpact
-            .registerConstantUse(new ConstantUse.init(initialValue));
-        // We don't need to generate code for static or top-level
-        // variables. For instance variables, we may need to generate
-        // the checked setter.
-        if (element.isStatic || element.isTopLevel) {
-          /// No code is created for this field: All references inline the
-          /// constant value.
-          return true;
-        }
-      } else {
-        // If the constant-handler was not able to produce a result we have to
-        // go through the builder (below) to generate the lazy initializer for
-        // the static variable.
-        // We also need to register the use of the cyclic-error helper.
-        registry.worldImpact.registerStaticUse(new StaticUse.staticInvoke(
-            closedWorld.commonElements.cyclicThrowHelper,
-            CallStructure.ONE_ARG));
-      }
-    }
-    return false;
-  }
-}