bfd: handle codepage when opening files on MinGW

Even if MS docs say that CP_UTF8 should always be used on newer
applications, forcing it might produce undefined filename if the
encoding isn't UTF-8.
MinGW seems to call ___lc_codepage_func() in order to retrieve the
current thread codepage.

bfd/ChangeLog:

        * bfdio.c (_bfd_real_fopen): Retrieve codepage with
        ___lc_codepage_func() on MinGW.
1 file changed