RFR 7176574 for 7u-dev: sun/security/krb5/auto/TcpTimeout.java failure

[Wang Weijun]

Please review the code change at

   http://cr.openjdk.java.net/~weijun/7176574/7u/webrev.00/

This is a backport of 3 jdk8 fixes on sun/security/krb5/auto/TcpTimeout.java

   7176574: sun/security/krb5/auto/TcpTimeout.java failed with solaris-i586
   http://hg.openjdk.java.net/jdk8/tl/jdk/rev/4435f8b20d08

   7162687: enhance KDC server availability detection
   http://hg.openjdk.java.net/jdk8/tl/jdk/rev/a2fc04c2dfc8

   7122169: TcpTimeout fail for various reasons
   http://hg.openjdk.java.net/jdk8/tl/jdk/rev/11698dedbe79

Please note that the jdk8 fixes include code changes to other files and are not suitable to be backported all. Here I only intend to backport changes for sun/security/krb5/auto/TcpTimeout.java and merge all of them as a backport of the last bug 7176574.

After this change, the test is identical to the one in jdk8 (and jdk9).

Thanks
Max