Request for Approval: Backport of 8203499: Uninitialised memory in WinAccessBridge.cpp:485

[Philip Race]

Request to backport this fix to 8u. Patch from 11 applied cleanly (after 
reshuffle)
All builds fine on internal build servers for 8.

bug : https://bugs.openjdk.java.net/browse/JDK-8203499
11 review thread : 
http://mail.openjdk.java.net/pipermail/swing-dev/2018-June/008649.html
11 webrev : http://cr.openjdk.java.net/~prr/8203499/ 
<http://cr.openjdk.java.net/%7Eprr/8203499/>
11 changeset : http://hg.openjdk.java.net/jdk/jdk/rev/10b8e57899b3
8 webrev : http://cr.openjdk.java.net/~prr/8203499.8u/

-phil.