libstdcpp-tests failing to build on some archs

[Jeff Johnson]

possible re-appearance of #1235

14:02 orc_emac> http://www.linuxbase.org/buildbot/builders/libstdcpp-test-s3
90/builds/8/steps/build/logs/stdio looked interesting dying: Bad exit
                 status from /var/tmp/rpm-tmp.Wj9cP1 (%install)
14:02 orc_emac> Found 2 missing .exe files, terminating build...
 ... 14:02 orc_emac> Missing:
14:02 orc_emac>
/opt/lsb/test/lib/libstdcpp_4.1.0/_ext_stdio_sync_filebuf_wchar_t_1.exe
14:02 orc_emac>
/opt/lsb/test/lib/libstdcpp_4.1.0/_ext_stdio_sync_filebuf_char_1.exe

14:35 mwichmann> mmm, that pattern looks a bit familiar
14:36 mwichmann> I'm almost sure we had some go-round about
                  stdio_sync_filebuf
14:38 mwichmann> okay, that's scary: there is such a bug (1235) but it's
                  from 7 years ago
14:42 mwichmann> seems there was a time when somebody stopped exposing
                  something they were supposed to, wonder if it came back?
14:43 orc_emac> that was my thought -- the opacity wanted was lost