Allow S->T <: dynamic->T

test/codegen/expect/dart/_js_helper.js

 var _js_helper;
 (function(exports) {
   'use strict';
   class NoSideEffects extends core.Object {
     NoSideEffects() {
     }
   }
   class NoThrows extends core.Object {
     NoThrows() {
     }
@@ skipping 82 matching lines @@
         let keys = this[_keys];
         for (let i = 0; i['<'](dart.dload(keys, 'length')); i = dart.notNull(i) + 1) {
           let key = dart.dindex(keys, i);
           f(dart.as(key, K), dart.as(this[_fetch](key), V));
         }
       }
       get keys() {
         return new _ConstantMapKeyIterable(this);
       }
       get values() {
-        return new _internal.MappedIterable(this[_keys], dart.as(((key) => this[_fetch](key)).bind(this), dart.throw_("Unimplemented type (K) → V")));
+        return new _internal.MappedIterable(this[_keys], dart.closureWrap(((key) => this[_fetch](key)).bind(this), "(K) → V"));
       }
     }
     dart.defineNamedConstructor(ConstantStringMap, '_');
     return ConstantStringMap;
   });
   let ConstantStringMap = ConstantStringMap$(dart.dynamic, dart.dynamic);
   let _protoValue = Symbol('_protoValue');
   let ConstantProtoMap$ = dart.generic(function(K, V) {
     class ConstantProtoMap extends ConstantStringMap$(K, V) {
       ConstantProtoMap$_(length, jsObject, keys, $_protoValue) {
@@ skipping 1604 matching lines @@
         hash = Math.random() * 0x3fffffff | 0;
         object.$identityHash = hash;
       }
       return hash;
     }
     static [_throwFormatException](string) {
       throw new core.FormatException(string);
     }
     static parseInt(source, radix, handleError) {
       if (handleError === null)
-        handleError = dart.as(_throwFormatException, dart.throw_("Unimplemented type (String) → int"));
+        handleError = dart.closureWrap(_throwFormatException, "(String) → int");
       checkString(source);
       let match = /^\s*[+-]?((0x[a-f0-9]+)|(\d+)|([a-z0-9]+))\s*$/i.exec(source);
       let digitsIndex = 1;
       let hexIndex = 2;
       let decimalIndex = 3;
       let nonDecimalHexIndex = 4;
       if (radix === null) {
         radix = 10;
         if (match !== null) {
           if (dart.dindex(match, hexIndex) !== null) {
@@ skipping 31 matching lines @@
           }
         }
       }
       if (match === null)
         return handleError(source);
       return parseInt(source, radix);
     }
     static parseDouble(source, handleError) {
       checkString(source);
       if (handleError === null)
-        handleError = dart.as(_throwFormatException, dart.throw_("Unimplemented type (String) → double"));
+        handleError = dart.closureWrap(_throwFormatException, "(String) → double");
       if (!/^\s*[+-]?(?:Infinity|NaN|(?:\.\d+|\d+(?:\.\d*)?)(?:[eE][+-]?\d+)?)\s*$/.test(source)) {
         return handleError(source);
       }
       let result = parseFloat(source);
       if (result.isNaN) {
         let trimmed = source.trim();
         if (dart.notNull(dart.equals(trimmed, 'NaN')) || dart.notNull(dart.equals(trimmed, '+NaN')) || dart.notNull(dart.equals(trimmed, '-NaN'))) {
           return result;
         }
         return handleError(source);
@@ skipping 1817 matching lines @@
   });
   exports.deferredLoadHook = null;
   // Function loadDeferredLibrary: (String) → Future<Null>
   function loadDeferredLibrary(loadId) {
     let urisMap = _foreign_helper.JS_EMBEDDED_GLOBAL('', dart.as(_js_embedded_names.DEFERRED_LIBRARY_URIS, core.String));
     let uris = dart.as(urisMap[loadId], core.List$(core.String));
     let hashesMap = _foreign_helper.JS_EMBEDDED_GLOBAL('', dart.as(_js_embedded_names.DEFERRED_LIBRARY_HASHES, core.String));
     let hashes = dart.as(hashesMap[loadId], core.List$(core.String));
     if (uris === null)
       return dart.as(new async.Future.value(null), async.Future$(core.Null));
-    let indices = dart.as(new core.List.generate(uris.length, (i) => i), core.List$(core.int));
+    let indices = dart.as(new core.List.generate(uris.length, dart.closureWrap((i) => i, "(int) → dynamic")), core.List$(core.int));
     let isHunkLoaded = _foreign_helper.JS_EMBEDDED_GLOBAL('', dart.as(_js_embedded_names.IS_HUNK_LOADED, core.String));
     let isHunkInitialized = _foreign_helper.JS_EMBEDDED_GLOBAL('', dart.as(_js_embedded_names.IS_HUNK_INITIALIZED, core.String));
     let indicesToLoad = indices.where((i) => !isHunkLoaded(hashes.get(i))).toList();
-    return dart.as(async.Future.wait(dart.as(indicesToLoad.map((i) => _loadHunk(uris.get(i))), core.Iterable$(async.Future))).then((_) => {
+    return dart.as(async.Future.wait(dart.as(indicesToLoad.map((i) => _loadHunk(uris.get(i))), core.Iterable$(async.Future))).then(dart.closureWrap((_) => {
       let indicesToInitialize = indices.where((i) => !isHunkInitialized(hashes.get(i))).toList();
       for (let i of indicesToInitialize) {
         let initializer = _foreign_helper.JS_EMBEDDED_GLOBAL('', dart.as(_js_embedded_names.INITIALIZE_LOADED_HUNK, core.String));
         initializer(hashes.get(i));
       }
       let updated = exports._loadedLibraries.add(loadId);
       if (dart.notNull(updated) && dart.notNull(exports.deferredLoadHook !== null)) {
         exports.deferredLoadHook();
       }
-    }), async.Future$(core.Null));
+    }, "(List<dynamic>) → dynamic")), async.Future$(core.Null));
   }
   // Function _loadHunk: (String) → Future<Null>
   function _loadHunk(hunkName) {
     let future = exports._loadingLibraries.get(hunkName);
     if (future !== null) {
-      return dart.as(future.then((_) => null), async.Future$(core.Null));
+      return dart.as(future.then(dart.closureWrap((_) => null, "(Null) → dynamic")), async.Future$(core.Null));
     }
     let uri = _isolate_helper.IsolateNatives.thisScript;
     let index = uri.lastIndexOf('/');
     uri = `${uri.substring(0, dart.notNull(index) + 1)}${hunkName}`;
     if (dart.notNull(Primitives.isJsshell) || dart.notNull(Primitives.isD8)) {
       return exports._loadingLibraries.set(hunkName, new async.Future(() => {
         try {
           new Function(`load("${uri}")`)();
         } catch (error) {
           let stackTrace = dart.stackTrace(error);
@@ skipping 299 matching lines @@
   exports.UnimplementedNoSuchMethodError = UnimplementedNoSuchMethodError;
   exports.random64 = random64;
   exports.jsonEncodeNative = jsonEncodeNative;
   exports.getIsolateAffinityTag = getIsolateAffinityTag;
   exports.loadDeferredLibrary = loadDeferredLibrary;
   exports.MainError = MainError;
   exports.missingMain = missingMain;
   exports.badMain = badMain;
   exports.mainHasTooManyParameters = mainHasTooManyParameters;
 })(_js_helper || (_js_helper = {}));