RFR 8232161: Align some one-way conversion in MS950 charset with Windows

[Ichiroh Takiguchi]

Hello.

Could you review the fix ?

Bug:    https://bugs.openjdk.java.net/browse/JDK-8232161
Change: https://cr.openjdk.java.net/~itakiguchi/8232161/webrev.01/

CSR 8233385 [1] was approved.

[1] https://bugs.openjdk.java.net/browse/JDK-8233385

Thanks,
Ichiroh Takiguchi
IBM Japan, Ltd.