Revert "fix #30462, update function_type tests to understand covariant generics"

tests/language_2/function_type/function_type26_test.dart

Index: tests/language_2/function_type/function_type26_test.dart
diff --git a/tests/language_2/function_type/function_type26_test.dart b/tests/language_2/function_type/function_type26_test.dart
index 548f4b7be70c40d1d5d52bbc78da2e506ce3c61d..71f7ca447416c74e3b0e17f750db80ea4a7a6874 100644
--- a/tests/language_2/function_type/function_type26_test.dart
+++ b/tests/language_2/function_type/function_type26_test.dart
@@ -321,10 +321,10 @@ class U26<T> {
       });
     }
     if (tIsInt || tIsBool) {
-      Expect.equals(true, m3 is F3<int>);
-      Expect.equals(true, m3 is F3<bool>);
-      Expect.equals(true, confuse(m3) is F3<int>);
-      Expect.equals(true, confuse(m3) is F3<bool>);
+      Expect.equals(tIsInt, m3 is F3<int>);
+      Expect.equals(tIsBool, m3 is F3<bool>);
+      Expect.equals(tIsInt, confuse(m3) is F3<int>);
+      Expect.equals(tIsBool, confuse(m3) is F3<bool>);
     }
   }