Move definition of Feature next to definitions of WorldImpact and Use

pkg/compiler/lib/src/common/resolution.dart

Index: pkg/compiler/lib/src/common/resolution.dart
diff --git a/pkg/compiler/lib/src/common/resolution.dart b/pkg/compiler/lib/src/common/resolution.dart
index 841e77cc6849f89595f94935144678683285dcfb..42f7b32bc57ec55f8954c29b5386a2acf8350267 100644
--- a/pkg/compiler/lib/src/common/resolution.dart
+++ b/pkg/compiler/lib/src/common/resolution.dart
@@ -10,7 +10,7 @@ import '../compiler.dart' show Compiler;
 import '../constants/expressions.dart' show ConstantExpression;
 import '../constants/values.dart' show ConstantValue;
 import '../core_types.dart' show CoreClasses, CoreTypes;
-import '../dart_types.dart' show DartType, InterfaceType, Types;
+import '../dart_types.dart' show DartType, Types;
 import '../elements/elements.dart'
     show
         AstElement,
@@ -36,6 +36,7 @@ import '../resolution/resolution.dart';
 import '../tree/tree.dart' show Send, TypeAnnotation;
 import '../universe/call_structure.dart' show CallStructure;
 import '../universe/world_impact.dart' show WorldImpact;
+import '../universe/feature.dart';
 import 'backend_api.dart';
 import 'work.dart' show ItemCompilationContext, WorkItem;
 
@@ -69,132 +70,6 @@ class ResolutionImpact extends WorldImpact {
   Iterable<dynamic> get nativeData => const <dynamic>[];
 }
 
-/// A language feature seen during resolution.
-// TODO(johnniwinther): Should mirror usage be part of this?
-enum Feature {
-  /// Invocation of a generative construction on an abstract class.
-  ABSTRACT_CLASS_INSTANTIATION,
-
-  /// An assert statement with no message.
-  ASSERT,
-
-  /// An assert statement with a message.
-  ASSERT_WITH_MESSAGE,
-
-  /// A method with an `async` body modifier.
-  ASYNC,
-
-  /// An asynchronous for in statement like `await for (var e in i) {}`.
-  ASYNC_FOR_IN,
-
-  /// A method with an `async*` body modifier.
-  ASYNC_STAR,
-
-  /// A catch statement.
-  CATCH_STATEMENT,
-
-  /// A compile time error.
-  COMPILE_TIME_ERROR,
-
-  /// A fall through in a switch case.
-  FALL_THROUGH_ERROR,
-
-  /// A ++/-- operation.
-  INC_DEC_OPERATION,
-
-  /// A field whose initialization is not a constant.
-  LAZY_FIELD,
-
-  /// A catch clause with a variable for the stack trace.
-  STACK_TRACE_IN_CATCH,
-
-  /// String interpolation.
-  STRING_INTERPOLATION,
-
-  /// String juxtaposition.
-  STRING_JUXTAPOSITION,
-
-  /// An implicit call to `super.noSuchMethod`, like calling an unresolved
-  /// super method.
-  SUPER_NO_SUCH_METHOD,
-
-  /// A redirection to the `Symbol` constructor.
-  SYMBOL_CONSTRUCTOR,
-
-  /// An synchronous for in statement, like `for (var e in i) {}`.
-  SYNC_FOR_IN,
-
-  /// A method with a `sync*` body modifier.
-  SYNC_STAR,
-
-  /// A throw expression.
-  THROW_EXPRESSION,
-
-  /// An implicit throw of a `NoSuchMethodError`, like calling an unresolved
-  /// static method.
-  THROW_NO_SUCH_METHOD,
-
-  /// An implicit throw of a runtime error, like
-  THROW_RUNTIME_ERROR,
-
-  /// The need for a type variable bound check, like instantiation of a generic
-  /// type whose type variable have non-trivial bounds.
-  TYPE_VARIABLE_BOUNDS_CHECK,
-}
-
-/// A use of a map literal seen during resolution.
-class MapLiteralUse {
-  final InterfaceType type;
-  final bool isConstant;
-  final bool isEmpty;
-
-  MapLiteralUse(this.type, {this.isConstant: false, this.isEmpty: false});
-
-  int get hashCode {
-    return type.hashCode * 13 +
-        isConstant.hashCode * 17 +
-        isEmpty.hashCode * 19;
-  }
-
-  bool operator ==(other) {
-    if (identical(this, other)) return true;
-    if (other is! MapLiteralUse) return false;
-    return type == other.type &&
-        isConstant == other.isConstant &&
-        isEmpty == other.isEmpty;
-  }
-
-  String toString() {
-    return 'MapLiteralUse($type,isConstant:$isConstant,isEmpty:$isEmpty)';
-  }
-}
-
-/// A use of a list literal seen during resolution.
-class ListLiteralUse {
-  final InterfaceType type;
-  final bool isConstant;
-  final bool isEmpty;
-
-  ListLiteralUse(this.type, {this.isConstant: false, this.isEmpty: false});
-
-  int get hashCode {
-    return type.hashCode * 13 +
-        isConstant.hashCode * 17 +
-        isEmpty.hashCode * 19;
-  }
-
-  bool operator ==(other) {
-    if (identical(this, other)) return true;
-    if (other is! ListLiteralUse) return false;
-    return type == other.type &&
-        isConstant == other.isConstant &&
-        isEmpty == other.isEmpty;
-  }
-
-  String toString() {
-    return 'ListLiteralUse($type,isConstant:$isConstant,isEmpty:$isEmpty)';
-  }
-}
 
 /// Interface for the accessing the front-end analysis.
 // TODO(johnniwinther): Find a better name for this.