Re-enable tests that were causing TimeoutExceptions on x86/x86-64.

Some libcore tests have been failing with a
java.util.concurrent.TimeoutException on ART Builbot's
x86/x86-64 concurrent collector configurations.  No longer
ignore these failures to see whether recent changes (namely
https://android-review.googlesource.com/#/c/204125) fixed
the issue.

Bug: 26507762
Change-Id: Ib188e194195fc11b539bd53a03db78ab80626f33
diff --git a/tools/libcore_failures_concurrent_collector.txt b/tools/libcore_failures_concurrent_collector.txt
index f347429..19a61dc 100644
--- a/tools/libcore_failures_concurrent_collector.txt
+++ b/tools/libcore_failures_concurrent_collector.txt
@@ -24,20 +24,6 @@
   bug: 26155567
 },
 {
-  description: "TimeoutException on host-{x86,x86-64}-concurrent-collector",
-  result: EXEC_FAILED,
-  modes: [host],
-  names: ["libcore.java.util.zip.DeflaterOutputStreamTest#testSyncFlushEnabled",
-          "libcore.java.util.zip.DeflaterOutputStreamTest#testSyncFlushDisabled",
-          "libcore.java.util.zip.GZIPInputStreamTest#testLongMessage",
-          "libcore.java.util.zip.GZIPOutputStreamTest#testSyncFlushEnabled",
-          "libcore.java.util.zip.OldAndroidGZIPStreamTest#testGZIPStream",
-          "libcore.java.util.zip.OldAndroidZipStreamTest#testZipStream",
-          "libcore.java.util.zip.ZipFileTest#testZipFileWithLotsOfEntries",
-          "libcore.java.util.zip.ZipInputStreamTest#testLongMessage"],
-  bug: 26507762
-},
-{
   description: "TimeoutException on hammerhead-concurrent-collector",
   result: EXEC_FAILED,
   modes: [device],