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

tests/language_2/function_type/function_type36_test.dart

Index: tests/language_2/function_type/function_type36_test.dart
diff --git a/tests/language_2/function_type/function_type36_test.dart b/tests/language_2/function_type/function_type36_test.dart
index addc8c2a4e35256f83b234cbd2d7d04470187beb..5ff2a9eb158b06c2fd4d1bc2c36ad8427c6e489a 100644
--- a/tests/language_2/function_type/function_type36_test.dart
+++ b/tests/language_2/function_type/function_type36_test.dart
@@ -318,10 +318,10 @@ class U36<T> {
       });
     }
     if (tIsInt || tIsBool) {
-      Expect.equals(tIsInt, m4 is F4<int>);
-      Expect.equals(tIsBool, m4 is F4<bool>);
-      Expect.equals(tIsInt, confuse(m4) is F4<int>);
-      Expect.equals(tIsBool, confuse(m4) is F4<bool>);
+      Expect.equals(true, m4 is F4<int>);
+      Expect.equals(true, m4 is F4<bool>);
+      Expect.equals(true, confuse(m4) is F4<int>);
+      Expect.equals(true, confuse(m4) is F4<bool>);
     }
   }