Regressions on trunk at revision 245909 vs revision 245908

[H.J. Lu]

New failures:

New passes:
FAIL: ext/stdio_filebuf/char/10063-1.cc (test for excess errors)
FAIL: ext/stdio_filebuf/char/10063-2.cc (test for excess errors)
FAIL: ext/stdio_filebuf/char/10063-3.cc (test for excess errors)
FAIL: ext/stdio_filebuf/char/2.cc (test for excess errors)
FAIL: ext/stdio_filebuf/requirements/explicit_instantiation.cc (test for excess errors)
FAIL: ext/stdio_sync_filebuf/char/12048-1.cc (test for excess errors)
FAIL: ext/stdio_sync_filebuf/char/12048-2.cc (test for excess errors)
FAIL: ext/stdio_sync_filebuf/char/12048-3.cc (test for excess errors)
FAIL: ext/stdio_sync_filebuf/char/1.cc (test for excess errors)