Missing explicit instantiations in libstdc++ (was Re: Unreviewed

[Benjamin Kosnik]

> You don't fully explain your reasoning.  However, this change seems a bit
> pessimistic.  If you want to test implicit instantiation, why not just do
> it on systems with weak linking semantics and provide the explicit needed
> when this isn't available?  We already have _GLIBCPP_SUPPORTS_WEAK in
> config.h, so this is trivial to implement.

I leave it to the g++ testsuite to test implicit instantiations. It is 
not the intention of the 22_locale/*.cc tests to deal with instantiations 
of any type. Instead, they should test that custom facets can be compiled 
correctly by the headers.

The 22_locale tests I was thinking of changing anyway, and this just 
helped convince me that it was a good idea. 

In my check in email to gcc-patches, I said that the locale testsuites 
were made consistent: some of the facet tests had compile-only, some 
didn't. Now they are all compile only. 

Sorry if this was unclear.

I'll look at integrating your patch into what was done last night shortly.

-benjamin