AIX testsuite failures

[Benjamin Kosnik]

> 	A very large number of libstdc++ testsuite failures have
> 	appeared
> for AIX.  Mainly missing template instantiations.

Sorry. My fault. In the ctype test reorganization, I forgot to guard the
wchar_t tests with _GLIBCPP_USE_WCHAR_T. I've since done so: future
testresults should be fine.

> 	Is there any way we can avoid introducing these failures before
> they happen?

I can test with wchar_t support disabled. I forgot to do so with the
initial patch check-in, but have verified things are working again.

best,
benjamin