Only set types of conditional expressions in strong mode.

pkg/front_end/testcases/rasta/duplicated_mixin.dart.direct.expect

Index: pkg/front_end/testcases/rasta/duplicated_mixin.dart.direct.expect
diff --git a/pkg/front_end/testcases/rasta/duplicated_mixin.dart.direct.expect b/pkg/front_end/testcases/rasta/duplicated_mixin.dart.direct.expect
index db8167ed340695cac0e1ddd3a538afd5037bd703..d1160d5e3ddcc3842dd6de671afdc6a11ee343e5 100644
--- a/pkg/front_end/testcases/rasta/duplicated_mixin.dart.direct.expect
+++ b/pkg/front_end/testcases/rasta/duplicated_mixin.dart.direct.expect
@@ -8,12 +8,20 @@ class Mixin extends core::Object {
     : super core::Object::•()
     ;
 }
-abstract class Object&Mixin = core::Object with self::Mixin {
+abstract class Object&Mixin extends core::Object implements self::Mixin {
+  field dynamic field = null;
+  constructor •() → void
+    : super core::Object::•()
+    ;
 }
-abstract class Object&Mixin&Mixin = self::Object&Mixin with self::Mixin {
+abstract class Object&Mixin&Mixin extends self::Object&Mixin implements self::Mixin {
+  field dynamic field = null;
+  constructor •() → void
+    : super self::Object&Mixin::•()
+    ;
 }
 class A extends self::Object&Mixin&Mixin {
   constructor •() → void
-    : super core::Object::•()
+    : super self::Object&Mixin&Mixin::•()
     ;
 }