[Bug libstdc++/43738] New: basic_file_stdio.cc uses ioctl on a fd, but not available on mingw32

["sherpya at netfarm dot it" <gcc-bugzilla at gcc dot gnu dot org>]

basic_file_stdio.cc in __basic_file<char>::showmanyc()
uses ioctl with FIONREAD, but the equivalent on win32 is ioctlsocket,
perhaps not usable here, because I think there is not support for socket here
in gcc (I'm wrong?)

anyway it does not compiles
I solve this by commenting out that part

    int __r = ioctl(this->fd(), FIONREAD, &__num);
    if (!__r && __num >= 0)
      return __num;

the problem still there since 4.3 iirc, I'm the only that noticed it?
there is something wrong in my setup?

my configure options:

../gcc/configure                            \
    --prefix=/mingw                         \
    --disable-bootstrap                     \
    --with-gnu-ld                           \
    --target=i686-pc-mingw32                \
    --with-tune=generic                     \
    --with-cpu=i686                         \
    --disable-cpp                           \
    --disable-win32-registry                \
    --disable-shared                        \
    --enable-static                         \
    --program-suffix=-4.6                   \
    --enable-version-specific-runtime-libs  \
    --enable-languages=c,c++                \
    --enable-cld                            \
    --enable-__cxa_atexit                   \
    --disable-werror                        \
    --disable-checking                      \
    --enable-multilib                       \
    --enable-threads=posix                  \
    --disable-libssp                        \
    --with-dwarf2                           \
    --disable-nls                           \
    --with-ppl                              \
    --disable-cloog                         \
    --enable-libgomp


-- 
           Summary: basic_file_stdio.cc uses ioctl on a fd, but not
                    available on mingw32
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: sherpya at netfarm dot it
 GCC build triplet: i686-pc-mingw32
  GCC host triplet: i686-pc-mingw32
GCC target triplet: i686-pc-mingw32


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43738