[RFR - backport]: 8203009 - IDN do not throw IAE when hostname ends with a trailing dot

[Martin Balao]

Hi,

Can I have a review for 8203009 [1]? This bug is a backport of 8020842 [2].

 * http://cr.openjdk.java.net/~mbalao/webrevs/8203009/8203009.webrev.00/
 * http://cr.openjdk.java.net/~mbalao/webrevs/8203009/8203009.webrev.00.zip

Testing: jdk/test/java/net/IDN/IllegalArg.java test is now passing in
JDK7. Internal security reproducer for JDK-8174873 is now passing in JDK7.

Thanks in advanced,
Martin.-

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[1] - https://bugs.openjdk.java.net/browse/JDK-8203009
[2] - https://bugs.openjdk.java.net/browse/JDK-8020842