[v3] Fix Werror breakage (maintainer-mode)

[Paolo Carlini]

> Can somebody enlighten me as to a proper locale_init.cc fix?

Yes, the warning is new and I'd like to understand whether the warning is worrisome or not, or even bogus. That's not clear to me, at the moment. As a LAST resort, the warning could be suppressed via the "usual" trick, something like:

    const char* __p = reinterpret_cast<const char*>(c_locale);
    return *reinterpret_cast<const locale*>(__p);

which I would consider a tad better than disabling -Werror selectively.

The unwind-pe.h change seems obviously safe to me.

Paolo.