Handle equivalence for generic mixins.

tests/compiler/dart2js/kernel/impact_test.dart

Index: tests/compiler/dart2js/kernel/impact_test.dart
diff --git a/tests/compiler/dart2js/kernel/impact_test.dart b/tests/compiler/dart2js/kernel/impact_test.dart
index 5fd2411e036e09f56319ec7d85920b5eb9c3db90..ccfce70f8ee8b2e7c933f0ebdaf6c46ef2c17b56 100644
--- a/tests/compiler/dart2js/kernel/impact_test.dart
+++ b/tests/compiler/dart2js/kernel/impact_test.dart
@@ -186,6 +186,8 @@ main() {
   testNativeField(null);
   testMixinInstantiation();
   testNamedMixinInstantiation();
+  testGenericMixinInstantiation();
+  testGenericNamedMixinInstantiation();
 }
 
 testEmpty() {}
@@ -630,6 +632,8 @@ class NativeClass {
 testNativeField(NativeClass c) => c.field;
 testMixinInstantiation() => new Sub();
 testNamedMixinInstantiation() => new NamedMixin();
+testGenericMixinInstantiation() => new GenericSub<int, String>();
+testGenericNamedMixinInstantiation() => new GenericNamedMixin<int, String>();
 ''',
   'sdk/tests/compiler/dart2js_native/helper.dart': '''
 import 'dart:_js_helper';
@@ -654,6 +658,14 @@ class Mixin2 {}
 class Sub extends Super with Mixin1, Mixin2 {}
 class NamedMixin = Super with Mixin1, Mixin2;
 
+class GenericSuper<X, Y> {}
+class GenericMixin1<X, Y> {}
+class GenericMixin2<X, Y> {}
+class GenericSub<X, Y> extends GenericSuper<X, Y>

[Siggi Cherem (dart-lang), 2017/02/10 22:11:22]

it might be interesting to test using different names for the type variables
too.

[Johnni Winther, 2017/02/12 09:46:43]

Done.

+    with GenericMixin1<X, Y>, GenericMixin2<X, Y> {}
+class GenericNamedMixin<X, Y> = GenericSuper<X, Y>
+    with GenericMixin1<X, Y>, GenericMixin2<X, Y>;
+
 const String _serializedScriptValue =
     'num|String|bool|'
     'JSExtendableArray|=Object';