HADOOP-9446. Support Kerberos SPNEGO for IBM JDK. (Yu Gao via llu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1513688 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5091. Merge change r1513700 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1513701 13f79535-47bb-0310-9956-ffa450edef68