RFR: JDK-8022178: System.console() throws IOE on some Windows

[Xueming Shen]

Hi,

Please help review the trivial change for 8022178.

http://cr.openjdk.java.net/~sherman/console/webrev

System.console() is not specified to throw an IOE. It is supposed to
return a null silently if there is no system console or anything goes
wrong to get one. The Windows implementation obviously has some
leftover code from the old/original implementation to throw a IOE
if it fails to get the std in/out handler in certain use scenario. The
proposed change is to simply remove the IOE throwing code and
return silently.

Thanks,
-Sherman