Support creating elements from IR nodes in JsKernelToElementMap

pkg/compiler/lib/src/common_elements.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.
 
 // TODO(sigmund): rename and move to common/elements.dart
 library dart2js.type_system;
 
 import 'common/names.dart' show Identifiers, Uris;
 import 'constants/values.dart';
 import 'elements/entities.dart';
@@ skipping 924 matching lines @@
       _findHelperFunction('throwAbstractClassInstantiationError');
 
   FunctionEntity _cachedCheckConcurrentModificationError;
   FunctionEntity get checkConcurrentModificationError =>
       _cachedCheckConcurrentModificationError ??=
           _findHelperFunction('checkConcurrentModificationError');
 
   FunctionEntity get throwConcurrentModificationError =>
       _findHelperFunction('throwConcurrentModificationError');
 
-  FunctionEntity _checkInt;
-  FunctionEntity get checkInt => _checkInt ??= _findHelperFunction('checkInt');
+  /// Return `true` if [member] is the 'checkInt' function defined in
+  /// dart:_js_helpers.
+  bool isCheckInt(MemberEntity member) {
+    return member.isFunction &&
+        member.isTopLevel &&
+        member.library == jsHelperLibrary &&
+        member.name == 'checkInt';
+  }
 
-  FunctionEntity _checkNum;
-  FunctionEntity get checkNum => _checkNum ??= _findHelperFunction('checkNum');
+  /// Return `true` if [member] is the 'checkNum' function defined in
+  /// dart:_js_helpers.
+  bool isCheckNum(MemberEntity member) {
+    return member.isFunction &&
+        member.isTopLevel &&
+        member.library == jsHelperLibrary &&
+        member.name == 'checkNum';
+  }
 
-  FunctionEntity _checkString;
-  FunctionEntity get checkString =>
-      _checkString ??= _findHelperFunction('checkString');
+  /// Return `true` if [member] is the 'checkString' function defined in
+  /// dart:_js_helpers.
+  bool isCheckString(MemberEntity member) {
+    return member.isFunction &&
+        member.isTopLevel &&
+        member.library == jsHelperLibrary &&
+        member.name == 'checkString';
+  }
 
   FunctionEntity get stringInterpolationHelper => _findHelperFunction('S');
 
   FunctionEntity get wrapExceptionHelper =>
       _findHelperFunction('wrapException');
 
   FunctionEntity get throwExpressionHelper =>
       _findHelperFunction('throwExpression');
 
   FunctionEntity get closureConverter =>
@@ skipping 329 matching lines @@
   // TODO(johnniwinther): Remove this when the resolver is removed.
   DartType getUnaliasedType(DartType type);
 
   /// Returns `true` if [member] a the synthetic getter `loadLibrary` injected
   /// on deferred libraries.
   bool isDeferredLoadLibraryGetter(MemberEntity member);
 
   /// Returns the metadata constants declared on [member].
   Iterable<ConstantValue> getMemberMetadata(MemberEntity member);
 }