Cross-compiling libstdc++, target_os issue

[vdm1e]

I am trying to cross-compile libstdc++ for sparc-sun-solaris2.8 from a
cygwin host.  I am running into a configuration issue of
"config/os/newlib" C++ includes being used instead of
"config/os/solaris/solaris2.7".  All other gcc, g++, and g77 targets
build and work fine.

I tried changing configuration options and building from gcc-3.3.1 and
gcc-3.2.3 sources, but always run into the same problem.  Here are my
configure options:

.../../configure -v --host=i686-pc-cygwin --build=i686-pc-cygwin
--target=sparc-sun-solaris2.8 --prefix=/usr --enable-languages=c,c++,f77
--disable-shared --enable-static --disable-multilib --with-gnu-ld
--with-gnu-as --enable-threads=posix
--with-headers=../../../../sparc/include
--with-libs=../../../../sparc/lib 
--enable-version-specific-runtime-libs

Does anybody know how to resolve this?

Thank you in advance for your help,
Dmitri