Remove duplicate entries with libcore expectation files.

Needed after N->AOSP drop.

test:art/tools/run-libcore-tests.sh
Change-Id: Icd7e20e8a6cff42aecf316e2a356d19bf9e5ee39
diff --git a/tools/libcore_failures.txt b/tools/libcore_failures.txt
index cbb6e1d..6472c8d 100644
--- a/tools/libcore_failures.txt
+++ b/tools/libcore_failures.txt
@@ -220,13 +220,6 @@
   names: [ "libcore.java.io.FileTest#testJavaIoTmpdirMutable" ]
 },
 {
-  description: "Made for extending, shouldn't be run",
-  result: EXEC_FAILED,
-  names: ["jsr166.CollectionTest#testEmptyMeansEmpty",
-          "jsr166.Collection8Test#testForEach",
-          "jsr166.Collection8Test#testForEachConcurrentStressTest"]
-},
-{
   description: "Flaky test",
   result: EXEC_FAILED,
   bug: 30107038,