Implement JS_INTERCEPTOR_CONSTANT

sdk/lib/_internal/lib/foreign_helper.dart

Index: sdk/lib/_internal/lib/foreign_helper.dart
diff --git a/sdk/lib/_internal/lib/foreign_helper.dart b/sdk/lib/_internal/lib/foreign_helper.dart
index ae919164b3170991f967de49ae681c060280d718..95b5907a50774cd26a5c1c670bac16b7eef66607 100644
--- a/sdk/lib/_internal/lib/foreign_helper.dart
+++ b/sdk/lib/_internal/lib/foreign_helper.dart
@@ -165,6 +165,14 @@ JS_CREATE_ISOLATE() {}
 JS_DART_OBJECT_CONSTRUCTOR() {}
 
 /**
+ * Returns the interceptor for class [type].  The interceptor is the type's
+ * constructor's `prototype` property.  [type] will typically be the class, not
+ * an interface, e.g. `JS_INTERCEPTOR_CONSTANT(JSInt)`, not
+ * `JS_INTERCEPTOR_CONSTANT(int)`.
+ */
+JS_INTERCEPTOR_CONSTANT(Type type) {}
+
+/**
  * Returns the prefix used for generated is checks on classes.
  */
 String JS_OPERATOR_IS_PREFIX() {}