[PATCH] PR libstdc++/13045

[Benjamin Kosnik]

>Now, while I was at it, I removed all the _GLIBCXX_DEMANGLER_STYLE_*
>macros too and put an equivalent in the new implementation_details
>class; this will allow user applications to have all possible formats
>in one application at their disposal without any code duplication/bloat.
>Hell, I might even add a foo<T> [with T = bar] style later.

Well then, even better. Please check this in.

-benjamin