RFR(xxs): 8145410: OutputStream::fill_to() does not work for error log

[Thomas Stüfe]

Hi all,

please review and sponsor this tiny change.

outputStream::fill_to() does not work as expected for the
staticBufferStream because its position never gets updated. That means that
fill_to() does not work in error reporting.

(I need this function because I am implementing an AIX-specific callstack
dumper and with the broken fill_to the output looks quite ugly)

Bug: https://bugs.openjdk.java.net/browse/JDK-8145410
webrev:
http://cr.openjdk.java.net/~stuefe/webrevs/8145410-fill_to-errorlog/webrev.00/webrev/

Thanks!

Thomas