Building crossGcc / gcc tools for Windows?

Just in case someone tries to compile crossGcc under cygwin in the future (yes I know cygwin builds are not my first choice either), here's what I had to change to get it to compile:

  while test "X"`$CONFIG_SHELL $0 --fallback-echo "X$testring" 2>/dev/null` 
             = "XX$testring" &&
          new_result=`expr "X$testring" : ".*" 2>&1` &&
          lt_cv_sys_max_cmd_len=$new_result &&
          test $i != 17#  1/2 MB should be enough
  do
    i=`expr $i + 1`
    testring=$testring$testring
  done

  while test "X"`$CONFIG_SHELL $0 --fallback-echo "X$testring"  2>/dev/null` 
             = "XX$testring" &&
          new_result=`expr "X$testring" : ".*" 2>&1` &&
          lt_cv_sys_max_cmd_len=$new_result &&
          test $i != 11#  PREVENT CYGWIN HANG, hopefully 11 iterations is still enough
  do
    i=`expr $i + 1`
    testring=$testring$testring
  done