Disable test 160 for (jvmti|redefine)-stress.

The test now uses VarHandles that are not supported
in these configurations.

Test: testrunner.py --target --64 --jvmti-stress -t 160
Test: testrunner.py --target --64 --redefine-stress -t 160
Bug: 37272822
Bug: 71781600
Change-Id: I3e064fe7a0aaaae404ed4ec8adad6de3b62ea526
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 1e0663d..3e6c40d 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -442,6 +442,7 @@
             ".*method-handle.*",
             ".*varhandle.*",
             ".*var-handle.*",
+            "160-read-barrier-stress",
             "716-jli-jit-samples",
             "1975-hello-structural-transformation",
             "1976-hello-structural-static-methods",