[7u6] Request for approval for CR 7167359 (tz) SEGV on solaris if TZ variable not set

[Seán Coffey]

Looking to port this simple fix from 8 to 7u. Fix is identical to jdk 8 one.

review thread  : 
http://mail.openjdk.java.net/pipermail/i18n-dev/2012-May/000615.html
jdk 8 changeset : http://hg.openjdk.java.net/jdk8/tl/jdk/rev/3e83229a3779

regards,
Sean.