On mingw-w64, long long (64bit wide) is larger than long (32bit wide).
Therefore we need some more specializations for string, docstring,
otextstream and << overloaded ostream functions. The configuration code
is by me, the source code changes by Shankar Giri Venkita Giri (bug 10053).
The problems the comments in the build systems refer to seem to have been
fixed for years. [1] says the checks in libstdc++ have been improved, and
all supported FreeBSD versions enable wchar_t support unconditionally in
libstdc++. Additionally, this needlessly impacts FreeBSD when libc++ is used
instead of libstdc++.
[1] http://gcc.gnu.org/onlinedocs/libstdc++/faq.html#faq.freebsd_wchar
