Re-land "fix #30462, update function_type tests to understand covariant generics"

tests/language_2/function_type/function_type46_test.dart

Index: tests/language_2/function_type/function_type46_test.dart
diff --git a/tests/language_2/function_type/function_type46_test.dart b/tests/language_2/function_type/function_type46_test.dart
index da2ed7a524fb44bc1126af20e5724c62437377c1..e04969bbe5656e573b9d9a8158937bf83d57484b 100644
--- a/tests/language_2/function_type/function_type46_test.dart
+++ b/tests/language_2/function_type/function_type46_test.dart
@@ -220,10 +220,10 @@ class U46<T> {
       });
     }
     if (tIsInt || tIsBool) {
-      Expect.equals(tIsInt, m0 is F0<int>);
-      Expect.equals(tIsBool, m0 is F0<bool>);
-      Expect.equals(tIsInt, confuse(m0) is F0<int>);
-      Expect.equals(tIsBool, confuse(m0) is F0<bool>);
+      Expect.equals(true, m0 is F0<int>);
+      Expect.equals(true, m0 is F0<bool>);
+      Expect.equals(true, confuse(m0) is F0<int>);
+      Expect.equals(true, confuse(m0) is F0<bool>);
     }
   }