Hint to get gcc to build up
the bootstrap compiler's bin directory at the front of $PATH, 
replace /usr/bin/gcc /usr/bin/cpp /usr/bin/g++ 
with symlinks to their counterparts in the bootstrap 
compiler directory (see note below re g++ and c++)

Make sure you've got gnu-binutils and gmake; then run 
contrib/download_prerequisites

Configure with --enable-languages='c ada c++' --build=x86_64-aux-solaris2.11 --enable-threads=posix 
--disable-libmudflap --disable-libgomp --disable-libssp 
--disable-libquadmath --disable-nls --disable-shared --disable-lto 
--disable-libstdcxx-pch --enable-multilib --with-gnu-as 
--with-as=/usr/bin/gas --without-gnu-ld --with-ld=/usr/bin/ld

gmake and then gmake install

