Allow S->T <: dynamic->T

test/codegen/expect/dart/_interceptors.js

 var _interceptors;
 (function(exports) {
   'use strict';
   let JSArray$ = dart.generic(function(E) {
     class JSArray extends Interceptor {
       JSArray() {
         super.Interceptor();
       }
       JSArray$fixed(length) {
         if (dart.notNull(!(typeof length == number)) || dart.notNull(length) < 0) {
@@ skipping 73 matching lines @@
         this.checkGrowable('remove');
         for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
           if (dart.equals(this.get(i), element)) {
             this.splice(i, 1);
             return true;
           }
         }
         return false;
       }
       removeWhere(test) {
-        _internal.IterableMixinWorkaround.removeWhereList(this, dart.as(test, dart.throw_("Unimplemented type (dynamic) → bool")));
+        _internal.IterableMixinWorkaround.removeWhereList(this, test);
       }
       retainWhere(test) {
-        _internal.IterableMixinWorkaround.removeWhereList(this, dart.as((element) => !dart.notNull(test(element)), dart.throw_("Unimplemented type (dynamic) → bool")));
+        _internal.IterableMixinWorkaround.removeWhereList(this, (element) => !dart.notNull(test(element)));
       }
       where(f) {
-        return new _internal.IterableMixinWorkaround().where(this, dart.as(f, dart.throw_("Unimplemented type (dynamic) → bool")));
+        return new _internal.IterableMixinWorkaround().where(this, f);
       }
       expand(f) {
-        return _internal.IterableMixinWorkaround.expand(this, dart.as(f, dart.throw_("Unimplemented type (dynamic) → Iterable<dynamic>")));
+        return _internal.IterableMixinWorkaround.expand(this, f);
       }
       addAll(collection) {
         for (let e of collection) {
           this.add(e);
         }
       }
       clear() {
         this.length = 0;
       }
       forEach(f) {
         let length = this.length;
         for (let i = 0; dart.notNull(i) < dart.notNull(length); i = dart.notNull(i) + 1) {
           f(dart.as(this[i], E));
           if (length !== this.length) {
             throw new core.ConcurrentModificationError(this);
           }
         }
       }
       map(f) {
-        return _internal.IterableMixinWorkaround.mapList(this, dart.as(f, dart.throw_("Unimplemented type (dynamic) → dynamic")));
+        return _internal.IterableMixinWorkaround.mapList(this, f);
       }
       join(separator) {
         if (separator === void 0)
           separator = "";
         let list = new core.List(this.length);
         for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
           list.set(i, `${this.get(i)}`);
         }
         return list.join(separator);
       }
       take(n) {
         return new _internal.IterableMixinWorkaround().takeList(this, n);
       }
       takeWhile(test) {
-        return new _internal.IterableMixinWorkaround().takeWhile(this, dart.as(test, dart.throw_("Unimplemented type (dynamic) → bool")));
+        return new _internal.IterableMixinWorkaround().takeWhile(this, test);
       }
       skip(n) {
         return new _internal.IterableMixinWorkaround().skipList(this, n);
       }
       skipWhile(test) {
-        return new _internal.IterableMixinWorkaround().skipWhile(this, dart.as(test, dart.throw_("Unimplemented type (dynamic) → bool")));
+        return new _internal.IterableMixinWorkaround().skipWhile(this, test);
       }
       reduce(combine) {
-        return dart.as(_internal.IterableMixinWorkaround.reduce(this, dart.as(combine, dart.throw_("Unimplemented type (dynamic, dynamic) → dynamic"))), E);
+        return dart.as(_internal.IterableMixinWorkaround.reduce(this, combine), E);
       }
       fold(initialValue, combine) {
-        return _internal.IterableMixinWorkaround.fold(this, initialValue, dart.as(combine, dart.throw_("Unimplemented type (dynamic, dynamic) → dynamic")));
+        return _internal.IterableMixinWorkaround.fold(this, initialValue, combine);
       }
       firstWhere(test, opt$) {
         let orElse = opt$.orElse === void 0 ? null : opt$.orElse;
-        return dart.as(_internal.IterableMixinWorkaround.firstWhere(this, dart.as(test, dart.throw_("Unimplemented type (dynamic) → bool")), orElse), E);
+        return dart.as(_internal.IterableMixinWorkaround.firstWhere(this, test, orElse), E);
       }
       lastWhere(test, opt$) {
         let orElse = opt$.orElse === void 0 ? null : opt$.orElse;
-        return dart.as(_internal.IterableMixinWorkaround.lastWhereList(this, dart.as(test, dart.throw_("Unimplemented type (dynamic) → bool")), orElse), E);
+        return dart.as(_internal.IterableMixinWorkaround.lastWhereList(this, test, orElse), E);
       }
       singleWhere(test) {
-        return dart.as(_internal.IterableMixinWorkaround.singleWhere(this, dart.as(test, dart.throw_("Unimplemented type (dynamic) → bool"))), E);
+        return dart.as(_internal.IterableMixinWorkaround.singleWhere(this, test), E);
       }
       elementAt(index) {
         return this.get(index);
       }
       sublist(start, end) {
         if (end === void 0)
           end = null;
         _js_helper.checkNull(start);
         if (!(typeof start == number))
           throw new core.ArgumentError(start);
@@ skipping 55 matching lines @@
         if (fillValue === void 0)
           fillValue = null;
         this.checkMutable('fill range');
         _internal.IterableMixinWorkaround.fillRangeList(this, start, end, fillValue);
       }
       replaceRange(start, end, iterable) {
         this.checkGrowable('removeRange');
         _internal.IterableMixinWorkaround.replaceRangeList(this, start, end, iterable);
       }
       any(f) {
-        return _internal.IterableMixinWorkaround.any(this, dart.as(f, dart.throw_("Unimplemented type (dynamic) → bool")));
+        return _internal.IterableMixinWorkaround.any(this, f);
       }
       every(f) {
-        return _internal.IterableMixinWorkaround.every(this, dart.as(f, dart.throw_("Unimplemented type (dynamic) → bool")));
+        return _internal.IterableMixinWorkaround.every(this, f);
       }
       get reversed() {
         return new _internal.IterableMixinWorkaround().reversedList(this);
       }
       sort(compare) {
         if (compare === void 0)
           compare = null;
         this.checkMutable('sort');
-        _internal.IterableMixinWorkaround.sortList(this, dart.as(compare, dart.throw_("Unimplemented type (dynamic, dynamic) → int")));
+        _internal.IterableMixinWorkaround.sortList(this, compare);
       }
       shuffle(random) {
         if (random === void 0)
           random = null;
         _internal.IterableMixinWorkaround.shuffleList(this, random);
       }
       indexOf(element, start) {
         if (start === void 0)
           start = 0;
         return _internal.IterableMixinWorkaround.indexOfList(this, element, start);
@@ skipping 1150 matching lines @@
   exports.Interceptor = Interceptor;
   exports.JSBool = JSBool;
   exports.JSNull = JSNull;
   exports.JSIndexable = JSIndexable;
   exports.JSMutableIndexable = JSMutableIndexable;
   exports.JSObject = JSObject;
   exports.JavaScriptObject = JavaScriptObject;
   exports.PlainJavaScriptObject = PlainJavaScriptObject;
   exports.UnknownJavaScriptObject = UnknownJavaScriptObject;
 })(_interceptors || (_interceptors = {}));