Revert "Fix language tests wrt. warnings."

tests/language/core_type_check_test.dart

Index: tests/language/core_type_check_test.dart
diff --git a/tests/language/core_type_check_test.dart b/tests/language/core_type_check_test.dart
index 4af259064f192c47076e0a22575a84099c01b20e..86f525b5275aae65ac0c67932448e39e01959004 100644
--- a/tests/language/core_type_check_test.dart
+++ b/tests/language/core_type_check_test.dart
@@ -12,21 +12,15 @@ check(value, expectComparable, expectPattern) {
 int inscrutable(int x) => x == 0 ? 0 : x | inscrutable(x & (x - 1));
 
 class A implements Comparable {
-  int compareTo(o) => 0;
 }
 
 class B {
 }
 
 class C implements Pattern {
-  matchAsPrefix(String s, [int start = 0]) => null;
-  allMatches(String s) => null;
 }
 
 class D implements Pattern, Comparable {
-  int compareTo(o) => 0;
-  matchAsPrefix(String s, [int start = 0]) => null;
-  allMatches(String s) => null;
 }
 
 main() {