RFR: 8239965: XMLEncoder/Test4625418.java fails due to "Error: Cp943 - can't read properly"

[Ichiroh Takiguchi]

Hello.

Could you review the fix ?

Bug:    https://bugs.openjdk.java.net/browse/JDK-8239965
Change: https://cr.openjdk.java.net/~itakiguchi/8239965/webrev.00/

Sorry for side effect.
Test4625418.java should skip Cp943 and x-IBM943 should be skipped
after JDK-8235834 [1] was integrated.

[1] https://bugs.openjdk.java.net/browse/JDK-8235834

Thanks,
Ichiroh Takiguchi
IBM Japan, Ltd.